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Guest Post – Future Small Arms


This guest article was written by a retired naval weapons engineer with some small arms experience, as an exercise in seeing how much information can be gleaned from the internet on small arms, in the interests of ‘Thinking Defence’.

Future Small Arms for the British Armed Forces.

BACKGROUND HISTORY. A brief reminder of the types of ammunition used since WW2 will provide a context for reaching agreement on a basic requirement for a new NATO standard small arms ammunition.

During WW2 the Americans used the 30-06″ for their rifles and machine guns, the .30″ (7.62×33) for their carbines, and the .32″, .38″, 9mm , and .45″ for their pistols and submachine guns. The British used the .303 round for their rifles, light machine gun and medium machine gun, (the home guard used the 30-06″), the 9mm Parabellum and .45″ACP for their submachine guns and the .38″ and .455″ for their revolvers.

The only rounds the US and the UK had in common were the .38″ & 9mm pistol rounds. Hardly standardisation.

Meanwhile, in 1943 the Germans introduced probably the first of the Intermediate power rounds. This was the 7.9mmx33 Kurz, developed as a compromise between their 7.92mmx57 rifle round and the 9mmx19 Parabellum pistol round also used in submachine guns. The low recoil force of this new round allowed it to be used in a light assault rifle in the fully automatic mode like a submachine gun while still being able to engage targets out to 300m when used as a rifle. The actual bullet diameter was 8.22mm (.324″) weight 123 grains. The 7.92mm size refers to the diameter of the bore between the lands of the rifling. The 33mm size refers to the case length.

The Soviets were quick to follow suit with their own Intermediate Power round. The 7.62mmx39mm round was a rimless bottlenecked intermediate cartridge that was introduced in 1944. The actual bullet diameter was 7.92mm (0.312″). Shortly after WW2 the world’s most widespread military rifle, the Kalashnikov AK47 was designed for this cartridge. The cartridge remained in service until the 70’s.

As expected, Intermediate Power rounds aroused great interest among the remaining Allies. The British were particularly impressed and in the late forties began development, with later help from Fabrique Nationale of Belgium, and Canada, of an intermediate round of their own. The British, by experimenting with bullet diameters, cartridge types, ballistic coefficients, etc, eventually produced the .280″ (7mm x43mm) round which not only had a sufficiently low recoil force of 10 J to permit an assault rifle to be used in fully automatic fire, but matched or exceeded the .303 full sized rifle round in performance at 1,000 yards due to its efficient ballistic coefficient. Britain also developed a bullpup assault rifle the EM-2, and a machinegun, the Taden (a belt fed Bren Gun), to take the new round; both were arguably ahead of their time.

This round was agreed by many to be years ahead of its day. Unfortunately, the USA considered it at the time to be too weak, and despite an agreement that the NATO member states would develop common small arms and ammunition in cooperation, the USA secretly developed their own .30 round. Britain was on the point of issuing the .280 round and its associated EM-2 rifle and Taden machinegun when an election brought Churchill back into office. He considered that standardisation was more important than individual weapon performance and in 1954 the British Army was obliged to accept the .30 American round, now designated the NATO 7.62x51mm round. The EM-2 could not be modified to accept the 7.62mm round and so Britain adopted the Belgian FN FAL self-loading rifle, expecting the USA to keep an agreement to do the same; but the US chose their own M14 rifle. The new 7.62x51mm round had much the same ballistic performance as the old British .303″.   The disadvantages of the 7.62x51mm round are its weight at 25.4 grams which limits the number of rounds the soldier can carry, the recoil energy of 16 joules which is too powerful for automatic fire in a handheld assault rifle, and the indifferent ballistic coefficient of the bullet which limits its effective range.

During the late 50’s the US army started a project to develop a 0.22″ calibre, high-velocity firearm to replace their M1/M2 0.30″ Carbines, the M3 and Thompson Submachineguns, the M1 Garand SLR, and the 1918 BAR light machine gun; despite having earlier rejected the .280×43 as too weak! However the US Army staff still insisted that they needed a more powerful round for the replacement of the M1 Garand and the 1918 BAR, and so the M14 SLR and M60 GPMG used the 7.62mmx51 round. For the new .22″ round Eugene Stoner was invited to scale down his experimental 7.62mm lightweight AR10 rifle. The calibre was to be 0.22″ with the bullet exceeding the supersonic speed at 500 yards and capable of penetrating one side of a US steel helmet at 500 yards. The wounding capability was to equal the M1/M2 Carbines, even though many in the army considered this was not powerful enough. The starting point was the high velocity .222″ Remington round, normally used for shooting small game at longer ranges and commonly called a ‘varmint’ round. After extensive development, the round that emerged in 1963 was a .223″ round, the 5.56mm, Ball, M193. This cartridge and its associated M16A1 Rifle, a development of Stoner’s Armalite AR-15 rifle, entered service in the USAF 1964.

In Vietnam, the 7.62mm M14 SLR proved to be too heavy and cumbersome for jungle warfare and was replaced by the Stoner M16A1. The US army also realised that for the same weight of 10kg, a soldier with a Kalashnikov was carrying 360 rounds compared with only 280 rounds for the 7.62mm M14.  When the M16A1 was introduced the US soldier was able to carry 600 rounds.

In action conditions, the 5.56mm round occasionally caused terrible wounds. This was at first thought to be caused by the bullet tumbling after striking but was later found to be due to the round fragmenting. The round complied with the Geneva Convention for small arms, which prohibited the use of rounds that expand or flatten, by being of full metal jacket construction. However, some countries question the legality of the 5.56mm round. In 1977, NATO members signed an agreement to select a small calibre cartridge developed by FN of Belgium from the M193, to be named the 5.56×45 NATO to complement the 7.62×51 NATO round.

The 5.56mm round in the M16A1 proved to be satisfactory in the shorter range jungle conditions of Vietnam, once reliability problems were solved. However, when faced with the longer ranges in the semi-arid areas of Iraq and Afghanistan using the later version of the round, the M855, troops started reporting that the rounds did not provide enough stopping power.  Troops engaging insurgents at less than 150m found that they were not causing lethal effects even with two hits and would not penetrate vehicle windscreens even with multiple hits at short range. Most of these reports probably came from users of the M4 carbine, a shorter, lighter version of the M16A2 assault rifle with a barrel reduced from 20″ to 14.5″. Tests have shown that M855 rounds must fragment to cause serious wound damage. If they do not fragment the effects are much reduced. The M855 must be travelling at 2,500 ft/sec to reliably fragment, but even with a full-length barrel the round will drop below this speed at 200m, and the shorter barrelled carbine round will drop below this speed at 150m.

As about half of the small arms attacks in Afghanistan were launched from 300-900 metres an answer had to be found for engaging the enemy at over 300m. The US Army answer to this problem was a heavily modified M16 series rifle intended to give the Squad Designated Marksman increased accuracy out to a range of 600m. Although the British Army use the SA80A2 rifle which has a longer barrel than that used by the M4 there were still complaints about its effectiveness at ranges over 200m. The British Army solution was a 7.62mmx51 ‘Marksman’ rifle, one per section. The weapon chosen was the American Lewis Machine Tool Co. LM308MWS, designated L129A1 in British service.

L129A1 Infantry Sharpshooter Rifle

Although suitable for standard M80 Ball the RG 155gr sniper round was so much better than the standard ball it was made the official issue round. The maximum effective range of this combination is 800m. The British Army also used the L86A2 Light Support Weapon as a marksman’s rifle. This version of the SA80 has a heavier 27.9″ barrel and a bipod. It was originally intended to provide fire support at section level but as it is not belt fed, and as an overheated barrel cannot be changed, it was not suitable for sustained fire and was replaced in the fire support role by the FN Minimi. The 5.56×45 FN Minimi can fire from both belt or box magazine feeds and has a quick change barrel and a Bipod. It fires from an open bolt to avoid cook-offs. Even so, some British Army sections carried 7.62mm FN MAG GPMGs as the section support weapon, despite the extra weight of both weapon and rounds.

Before I close this section, a few words on the relative reliability of the different self-loading actions.

The Kalashnikov AK 47, the M1 Garand, the British Bren Gun, and the FN MAG GPMG, all noted for their reliability and durability, all use a Long Stroke Piston forced to the rear by expanding propellant gas bled through a port in the barrel near the muzzle end. The piston acts directly against the bolt carrier to eject the spent cartridge, and then the bolt carrier and piston move forward driven by the return spring to load the next round. As the bolt carrier is driven all the way to the rear by the piston this makes for more reliable ejection and reloading. Propellant gases are kept well away from the receiver. Even after 70 years, AK47s remains the most popular and widely used assault rifle in the world due to their substantial reliability under harsh conditions. The disadvantage is an increase in weight, but not excessively so. AK 47s are not noted for their accuracy which it is thought can be upset by the increased mass of reciprocating parts during firing which takes place with the long stroke piston above the barrel, although this does not seem to affect the accuracy of the Bren Gun and the FN MAG GPMG.

The SA80 which employs features of the Stoner AR18 uses the Short Stroke Piston method. The short stroke piston is also driven by propellant gas bled through a port in the barrel. The short stroke piston imparts a short sharp blow to the bolt carrier which continues to the rear under its own kinetic energy. The advantages are weight saving and lower reciprocating mass while firing. The disadvantage is that fouling in the receiver on the path of the bolt carrier can affect its rearwards movement and thus adversely affect ejection or reloading.

The AR15 (M16A2) uses the direct impingement method. The direct impingement method of operation vents hot gas from partway down the barrel through a tube to the working parts of a rifle where they directly impinge on the bolt carrier. The advantage is a simpler and lighter mechanism. Another advantage is that the moving parts are placed in-line with the bore meaning that the line of sight is not disturbed as much by reciprocating mass. The disadvantage is that the hot propellant gas (and the accompanying fouling) is blown directly into the action parts. The operation increases the amount of heat that is deposited in the receiver while firing, which can burn off lubricants while depositing fouling. The bolt, extractor, ejector, pins, and springs are also heated by the same high-temperature gas. These combined factors reduce the service life of these parts, and the mean time between failures. Early models of the M16A2 had problems with ejection due to this cause.

The above story shows how battle experience, combined with weapon and ammunition development, has lead to the proliferation of both weapons and ammunition moving away from the benefits of standardisation.

Short-Term Futures

Within the next ten to fifteen years, from 2018, the armies of the USA, Canada, UK, Germany, and France will need to replace or at least update their small arms.  However the relative weakness of the defence budgets of both the USA and the UK, and/or the lack of priority for new infantry weapons while both countries are avoiding major ground conflicts following wars in Iraq and Afghanistan, means that in the short term all that can be expected are improvements in the existing status quo; i.e. a continuation of 5.56mm and 7.62mm ammunition and their associated weapons.

The shortcomings in the present weapons and ammunition are as follows:

  • Lead cores need to be eliminated from all rounds in order to comply with environmental standards.
  • The 7.62mm recoil force of 16 Joules is too severe for the automatic fire to be used in handheld assault rifles. The hard recoil causes some operators to find it difficult to maintain even single shot accuracy.
  • The weight of the 7.62mm round at 25.4 grams means that for a 10-kilogram load, a 7.62 user can carry only 390 rounds compared with 613 rounds for the AK47, or 813 rounds for the 5.56mm SA80A2. This must be viewed in the context that the probability of making a hit is proportional to the number of rounds available.
  • The GPMG is considered by many to be too heavy to act as the Section Light Machine Gun, and the FN 5.46mm Minimi has been issued instead, despite reservations about its effective range. Some units do carry the GPMG as the section light machine gun despite the extra weight.
  • Reports from Afghanistan indicate that the 5.56 round was not powerful enough to engage opposition at ranges over 300 metres. As half the engagements with Taliban fighters took place at ranges from 300 to 600 metres the NATO forces were out-ranged. In the UK the problem was partially overcome by issuing a 7.62mm rifle to a designated marksman in each Section.
  • Currently, the Infantry units and their suppliers have the logistic problem of requiring three different types of small arms ammunition to be supplied, namely 9mm, 5.56mm and 7.62mm. Cost and manpower savings up the logistic chain back to the manufacturer could be made if the assault rifle and the machine gun used the same ammunition. This ideal was achieved by Britain in the 1940s with the .280 (7mm) round for the EM2 rifle and Taden machine gun, both fully developed, but then abandoned for standardisation reasons when the Americans adopted the 7.62mm round.

Some of these shortcomings can be addressed in the near term and the most likely changes will be:-

  • The imminent introduction of the steel-tipped, copper cored, US developed M855A1 5.56mm and M80A1 7.62mm Enhanced Performance Rounds or a similar British equivalent round. They not only eliminate lead from their construction on environmental grounds but are claimed to have improved penetration of steel targets, more consistent wound effects in soft targets, and better accuracy.
  • In the longer term, development is nearing completion in the USA of polymer cartridge cases instead of brass cases. They offer a 35% reduction in weight over brass cases and are claimed to offer cooler operation of the chamber when firing.
  • Approval of the SA80A3 Upgrade of the existing assault rifle is nearing completion. The changes include:-
    • A safety stud placed above the change lever on the trigger mechanism housing to ensure that this lever does not over-rotate.
    • The Weaver rail on top of the upper receiver being replaced a full-length Picatinny rail – this will allow the day sight and night sight to be mounted in tandem.
    • A new foregrip, or quad rail, as part of the new full-length rail which will be attached slightly differently to the current one allowing the barrel to be more free-floating than at present, to improve accuracy and consistency.
    • Redesign of the A3 upper receiver for improved reliability and maintainability over the current A2 variant.
    • A colour change to Dark Earth for better compatibility with MTP camouflage uniforms.
    • There may be weight saving measures not mentioned above, for example, a titanium piston.
  • Introduction of a Lightweight GPMG. A lightweight version of the L7A2 GPMG has been developed by H&K with a reduction in weight of 1.8kg (4lbs). Changes include:-
    • A fluted barrel,
    • A Picatinny rail for sights on the top cover,
    • A folding butt,
    • An improved feed tray.
    • A Dark Earth coloured receiver body matching the new MTP camouflage.

This gun does not include the titanium receiver body which is still under study at Cranfield. If this development is practical and affordable the weight saving would be around 3kg (6.6lb). The Lightweight GPMG remains a stated Army requirement.

The above improvements are expected to extend the life of 5.56mm and 7.62mm ammunition and weapons until approximately 2035/40. This will allow time for the development of the next generation of small arms ammunition and associated weapons, which has already started in the USA.

Long-Term Futures

Such is the predominance of the US arms industry, the influence of their supporting political lobbyists and the sheer size of their armed forces, that any changes in NATO standard ammunition must have the support of the USA. In practice, this means that any developments in NATO ammunition will take place in the USA. Even if the Europeans proved to have a better design of ammunition the Americans are unlikely to accept it, despite getting it wrong in 1954 with the 7.62 which was too heavy with excessive recoil force and poor ballistic coefficient, and again in 1977 with the 5.56 which was too light, easily deflected, great for prairie dogs but reportedly not so good for Taliban.

It is therefore in the interests of the UK to agree as soon as possible with Canada, Germany, France and any other NATO countries, their basic Future NATO Small arms Ammunition (FNSA) Design Requirement. They should then use every ounce of their collective influence to persuade the USA to base their developments on their jointly agreed requirement.

Once the FNSA Round has been developed and agreed NATO countries, singly or in partnership, should be free to make their own ammunition to this standard, and design and make their own weapons to use this ammunition. The USA may well ask for contributions to the development costs of this ammunition.

The UK and other NATO countries may well have different Infantry Doctrines to the USA and therefore may not use the same weapons even though using the same ammunition. For example, proposals emerging from the USA include a suggestion for ALL infantry weapons to have a range of 1,200 metres which suggests replacing the assault rifle with something more elaborate. Another proposal is that the assault rifle fires 20mm grenade rounds which can be set to explode at a range set by a laser range finder built into the weapon, which also has a conventional rifle set below the 20mm barrel (ie two magazines will be required). It appears that the USA is heading for more complex, bulkier, and costly weapons.

It is for consideration that in the UK the equipment for the infantry section has already become too heavy and complex. They are already required to carry their individual weapons and ammunition, a range of day and night vision aids, radio communication aids, body armour, bayonet, hand grenades, entrenching tool, rations, kit, etc. plus as required the 27lb MBT LAW antitank weapon and 19lb Matador anti-structure munitions. What is required is a return to a more “nimble” soldier at section level with light simple robust weapons. What can weapons developments do to reduce this problem, apart from making lighter weapons and ammunition? It is for consideration that he need for indirect fire support at the lowest level could be met by supplying each section with a lightweight handheld target acquisition sight no bigger than a pair of binoculars, which could radio target data to a handheld mortar computer no bigger than a mobile phone, for the control of 60mm mortars held at platoon level. The technology to do this should be achievable by 2035. The 60mm mortar bomb would provide a much greater terminal effect than either the proposed US 20mm grenade rounds or the existing 40mm grenades fired from an under-slung tube launcher on the assault rifle. This will relieve the Section of a load of transporting a quantity of 40mm grenades and the H&K under-slung launchers and their sights on two of the weapons.

This paper, therefore, addresses the UK requirements for Future Small Arms. The main aims will be:-

  1. To introduce a common ammunition for both Assault Rifles and General Purpose Machine Guns.
  2. To introduce an Assault Rifle with a maximum effective range of 800m, and a General Purpose Machine Gun with a maximum effective range of 1,200m.
  3. To reduce as far as possible the weight of individual rounds of ammunition and weapons consistent with achieving the maximum effective ranges above.

Four outline specifications;-

  • Annexe A, a draft outline specification for the Future NATO Smallarms Ammunition  (FNSA).
  • Annexe B, a draft outline specification for a Future British Assault Rifle.
  • Annexe C, a draft outline specification for a Future British General Purpose Machinegun.
  • Annexe D, a draft outline specification for a Future Self Defence Weapon.

Finally, the United States should be made aware that if they are not prepared to design and develop a round to meet the FNSA basic requirements of the rest of the NATO countries, there may have to be two standards, one for the USA and another for the rest of NATO. This would be a retrograde step.

In considering the design of new ammunition and weapons it is as well to remember the words of Kalashnikov himself when asked about the design process. “A lot of Russian soldiers ask me how new weaponry is designed. This a very difficult question. Each designer has his own paths, his own successes and failures. But one thing is clear; before attempting to create something new it is vital to have a good appreciation of everything that already exists in this field. I myself have had many experiences confirming this to be so.” ( Kalashnikov modelled the long stroke action of the AK47 on the US M1 Garand SLR)

Annex A. Outline Design Requirement for the Future NATO Smallarms Ammunition (FNSA).

This outline requirement acknowledges the predominance of the United States of America in developing NATO Standard ammunition. It acknowledges, therefore, the developments that have already been carried out by them.

American studies in 2006 by the Joint Services Wound Ballistics-Integrated Projects Team recommended a calibre in the  6.5mm to 7mm range.

The Textron Company has, on behalf of the US Army, spent ten years developing 6.5mm(.266″) Cased Telescopic (6.5mm CTA) rounds which are reaching maturity. They have also developed a prototype Machinegun and a prototype Carbine (assault rifle) in which to prove the ammunition, but would probably not meet British requirements. Much more testing is required, but the results so far look promising.

An outline design requirement for Future NATO Smallarms Ammunition (FNSA) is proposed below. This is for discussion with other NATO countries, prior to approaching the USA.

  1. A Cased Telescopic Ammunition (CTA) round shall be developed, using as a starting point the 6.5mm, 8oz (135grain) bullet already developed by Textron (this low drag bullet is only 5 grains or 3.6% lighter than the 7.62mm but is 20% longer and therefore has a better ballistic coefficient). It shall be suitable for small arms use, ranging from assault rifles used in single shot or automatic fire out to 600m, through designated marksman use out to 800m, to suppressive fire from light and medium machineguns out to 1,200m. It shall have sufficiently low recoil energy to permit the assault rifle to be fired comfortably in automatic fire while matching or exceeding the accuracy, penetration and residual energy requirements stated below.
  2. The details of the barrels required to meet the performance standards shall be defined by the ammunition designer and used to confirm the performance standards. Two barrels are required, the first suitable for an individual assault rifle using either automatic fire or single aimed shots out to 800m, and the second for sustained suppressive fire in a machinegun out to 1,200m. The barrel descriptions shall include materials, chamber dimensions, barrel length, rifling twist, bore measured between the top of the lands of the rifling, and the finish of the chamber and bore. In the case of the ammunition being used in a short carbine barrel, the drop in performance standards, and any changes in rifling required shall be defined.
  3. Low overall ammunition weight is important regarding the number of rounds that can be carried as this reflects on the hit probability of rounds carried by the soldier. Therefore the maximum weight of the new round shall not exceed 15 grams (7.62mm = 25.4grams), and a 20 round loaded magazine shall not exceed 450grams (1lb).  One kg of 7.62mm rounds would be 280 rounds but 1Kg of 6.5mm CTA would be 475 rounds. However low ammunition weight shall not over-ride the need to meet the ballistic performance targets.
  4. The recoil energy per round shall not exceed 10 Joules.
  5. The range for the penetration of one side of a steel helmet shall be not less than 800m for the shorter barrel and 1,200M for the longer barrel.
  6. The residual energy at 1,200m shall be not less than 300 foot-pounds. (7.62mm = 230ftlbs)
  7. The vertex height for 600m range shall not exceed 1m.
  8. Accuracy shall be less than 1 MOA in test conditions using the standard barrels defined above.
  9. The SAMMI chamber pressure shall not exceed 65,000 psi.
  10. For environmental reasons, the bullet shall contain no lead or radioactive material.
  11. For legal reasons, the bullet shall not fragment on contact with human tissue at any range.
  12. The ammunition shall be suitable for use in either polymer type box magazines or belt feed.
  13. The ammunition shall be suitable for use in temperatures between +50°C and -50°C.

Annex B. Outline Design Requirement for a Future British Assault Rifle (FBAR).

  1. THE ACTION. The FBAR shall employ a rotating bolt, gas operated long stroke piston, and fire from a closed bolt. The action shall operate in either single shot self-loading mode or fully automatic mode with a rate of fire between 600 and 700 rounds per minute. The cocking lever shall not reciprocate when firing. The bolt carrier shall remain in the rear position when the last round is fired from the magazine, and be ready to fire again when the magazine is replaced. The exhaust gas shall not impinge on the operator’s face or hands. The FBAR shall use a ‘bullpup’ configuration with the magazine behind the pistol grip in order to reduce the overall length of the weapon. It shall use a detachable 20 round polymer magazine. In order to achieve the required degree of accuracy and muzzle energy the FBAR shall have a barrel length up to but not exceeding 20″, cold forged with a chrome lining for long life and easy cleaning, and chambered for the 6.5mm CTA round. The barrel shall be free floating as much as the gas take-off will allow. It shall be fitted with a slotted flash eliminator and shall accept the British L3A1 socket bayonet.
  2. THE FURNITURE. The stock shall be made of synthetic material and be neat, uncluttered and easy to clean, and in a Dark Earth colour matching the new MTP camouflage. The stock shall be resistant to abrasion, impact, oils, fuels, greases, acids, strong alkalis, moisture, UV light, high humidity and extremes of temperature between +50° and -50°C. The straight buttstock shall be in line with the axis of the bore such that the recoil force will not cause the muzzle to climb between shots, and shall be positioned so as to give a comfortable alignment of the eye with the sight line.  The fore-end shall cover the top of the barrel to prevent heat distortion of the line of sight. The edges of the top, bottom and sides of the for-end shall be parallel with the barrel and fitted with Picatinny rails on the top, bottom and sides parallel to the barrel for accessories. The rail on the top shall be long enough to permit the use of day sight and night sight in tandem. A vertical handgrip with a telescopic bipod shall be fitted to the bottom Picatinny rail. There shall be storage for cleaning gear and oil bottle. There shall be provision for a sling.
  3. THE CONTROLS. The mode of fire (single shot or automatic) shall be selected by a two position lever which shall be operated without taking the hand off the pistol grip. A manual cross bolt safety catch shall be fitted above the pistol grip. The FBAR shall be suitable for use by both left handed and right handed operators. Controls such as the mode selector, safety-catch, magazine catch and cocking lever shall operable by either left handed or right handed shooters or readily interchanged between the two. The cartridge case ejection shall be readily changeable between the left side and right sides. The magazine catch shall be positioned so as to avoid accidental release of the magazine. The trigger and the controls listed above shall be capable of being operated wearing cold weather gloves. The trigger shall have a two-stage crisp action with a first stage pull weight of 5 to 8 lbs, and a second stage pull weight of 1 to 1.5lbs.
  4. THE SIGHTS. The optical sight(s) shall be mounted on a Picatinny rail on the top of the receiver long enough to permit a day sight and night sight to be fitted in tandem. The optical sight is expected to be an Elcan Lightweight Day Sight (LDS) with 4x magnification. On top of this sight is a low profile ‘Red Dot’ Non-Magnifying Reflector Close Quarters Battle (CQB) sight. The section’s Designated Marksman will probably be issued with a more powerful ACOG 6×48 sight complete with CQB sight (his weapon will be otherwise the same as the rest of the section).   In case the optical sights fail the FBAR shall have ‘flip-up’ iron sights, with an aperture back-sight adjustable for ranges between 100m and 600m, and a blade foresight on the front of the receiver.
  5. THE DIMENSIONS. The overall length of the FBAR shall be not more than 30″ (752mm). The length of pull from butt to trigger shall be 15″. The fore-end shall extend at least 10″ forward from the trigger. The maximum weight of the FBAR, with a loaded magazine, Elcan Lightweight Day Sight, and sling attached, shall be not more than 8 lb (3.63kg) .
  6. THE ACCESSORIES. Accessories supplied with each FBAR shall be, a Blank Firing Attachment, a Blank Firing Magazine, an Adjustable Sling, an Oil Bottle, and Cleaning Gear.
  7. RELIABILITY. The FBAR shall operate reliably when subjected to all the appropriate MOD tests for resistance to sand, mud, rain, immersion in salt water, snow, and temperatures between +50° and -50°C; plus drop tests, cook-off tests, etc. The FBAR shall achieve an average reliability of 25,000 mean rounds between failures.
  8. MAINTAINABILITY. Field strip, cleaning and re-assembly of the FBAR shall be straightforward with no tools required. Securing pins shall be captive to avoid loss. Complete strip, refurbishment and re-assembly by armourers shall not require the use of special-to-type gauges or tools.
  9. PERFORMANCE. The FBAR shall be capable of placing 6 consecutive rounds in a 4″ square at 200m. The Maximum Effective range of the FBAR shall be 600m when fitted with an optical sight with x4 magnification, and 800m when fitted with an optical sight of x6 magnification.
  10. CARBINE VERSION. A Carbine version with an overall length of 22″ and using as many components as possible of the FBAR shall be introduced for use by crews of all manner of vehicles, gunners, crew-served weapons operators, helicopter crews, signallers, infantry NCOs, special forces, etc.
  11. CONSTRUCTION. The feasibility should be examined by making a one piece combined receiver and furniture using the 3D printing technique should suitable material be developed.

 Annex C. Outline Design Requirements for a Future British General Purpose Machinegun (FGPMG).

  1. THE ACTION. The FGPMG shall employ a tilting block bolt, gas operated long stroke piston, and fire from an open bolt. The FGPMG shall use a linked belt feed, fitted ahead of the trigger. The means of inserting a belt shall be easy to operate and difficult to get wrong. The bolt carrier shall remain in the rear position when the last round is fired from the belt and be ready to fire again when a new belt is fitted. The action shall operate in fully automatic mode only, with a rate of fire between 600 and 1,000 rounds per minute. The cocking lever shall not reciprocate when firing. An eight position gas regulator valve shall adjust the rate of fire. The exhaust gas shall not impinge on the operator’s face or hands. In order to achieve the required degree of accuracy and muzzle energy, the FGPMG shall have a barrel up to but not exceeding 24″, cold forged with a chrome lining for long life and easy cleaning, chambered for the 6.5mm CTA round. The barrel shall be fitted with a carrying handle, slotted flash suppressor and a blade foresight. The barrel shall be easily removed and replaced using the carrying handle to avoid touching the hot barrel. Changing a barrel shall not take longer than 6 seconds.
  2. THE FURNITURE. The weapon shall be neat, uncluttered and easy to clean. The Butt-stock and Pistol Grip shall be made of synthetic material that is resistant to abrasion, impact, oils, fuels, greases, acids, strong alkalis, moisture, UV light, high humidity and extremes of temperature between +50° and -50°C. The Butt-stock, Receiver Body and Pistol Grip shall be finished in a Dark Earth colour matching the new MTP camouflage. The butt shall be positioned so as to give a comfortable alignment of the eye with the sight line and shall be able to be folded and clipped back against the receiver body to reduce the weapon length if required. There shall be provision to attach a sling.  A folding bipod, adjustable for height, shall be attached to the front of the weapon and shall be folded back and clipped in place when not in use. There shall be provision for a sling, and storage of an oil bottle and cleaning gear
  3. The FGPMG shall be capable of being configured in either of two roles, namely as a Light Machinegun or as a Medium Machinegun. The Light Machinegun shall use a buttstock and fire from a bipod. The Medium Machinegun shall fire from a tripod and may have the buttstock and bipod removed if preferred. An attachment bush, similar to that on the FN MAG GPMG, with a bore of xx mm is to be built into the lower part of the receiver for attachment to the tripod or other mounts.
  4. THE DIMENSIONS. The overall length of the FGPMG shall be not more than 38″ (752mm). The length of pull from butt to trigger shall be 15″. The maximum weight of the FGPMG, unloaded, shall be not more than 18 lb (8.2kg).
  5. THE CONTROLS. A manual cross bolt safety catch shall be fitted above the pistol grip. The trigger shall have a two-stage crisp action with a first stage pull weight of 5 to 8 lbs, with a second stage pull weight of 1 to 1.5lbs. The FGPMG shall be suitable for use by both left handed and right handed operators. Controls such as the safety-catch, magazine catch and cocking lever shall be capable of operation by either left handed or right handed operators. The trigger, cocking lever, safety catch, cartridge belt loading arrangements and barrel changing arrangements shall permit operation while wearing cold weather gloves.
  6. THE SIGHTS. A Picatinny rail long enough to permit a day sight and night sight to be fitted in tandem shall be fitted along the top of the receiver for sights or other accessories. The rail shall be suitable for current sights such as the Elcan 4x Lightweight Day Sight, the ACOG 6×48 LDS and the Viper2 Thermal Imaging Sight. Iron sights shall consist of a forward blade which is part of the barrel assembly and adjustable for windage. A folding aperture sight shall be hinged at the rear of the receiver body, adjustable for ranges from 400m to 1,800m at 100m intervals. When the sight is folded down a larger aperture sight is to be presented for CQB. A bracket shall be fitted on the left rear of the receiver body to take a C2 Indirect Fire Sight.
  7. THE ACCESSORIES. Accessories supplied with each FGPMG shall be, a Blank Firing Attachment, an Adjustable Sling, an Oil Bottle, Cleaning Gear, and a Spare Barrel.
  8. RELIABILITY. The FGPMG shall operate reliably when subjected to appropriate tests for resistance to sand, mud, rain, immersion in salt water, snow, and temperatures between +50° and -50°C., plus drop tests, cook-off tests etc. The FGPMP shall achieve an average reliability of 25,000 mean rounds between failures.
  9. MAINTAINABILITY. Field strip, cleaning and re-assembly of the FGMG shall be straightforward with no tools required. Securing pins shall be captive to avoid loss. Complete strip, refurbishment and re-assembly of the FGPMG by armourers shall not require the use of special-to-type gauges or tools.
  10. PERFORMANCE. The FGPMG shall place 6 consecutive rounds in a 4″ square at 200m. The maximum effective range of the FGPMG shall be 1,200m.
  11. CONSTRUCTION. The feasibility should be examined by making a one-piece combined receiver and furniture using the 3D printing technique should suitable material be developed.

Annex C. Outline Self Defence Weapon (SDW) Requirement for Support Troops.

The new British Future British Assault Rifle (FBAR) using the new 6.5mm CTA round, is relatively costly and requires extensive periods of training and practice in order to achieve maximum effectiveness.

There is a need therefore to provide a less costly, lighter, simpler weapon which does not require extensive training, for the self defence of Support Troops, such as the Logistic Corps, Adjutant Generals Corps and Aircraft Ground Crew, etc. (An example being the M1 0.380″ Carbine issued to Support Troops in the US Armed Forces in WW2.)

A less costly and lighter weight ammunition is required as well, and there is a need to standardise on the range of ammunition supplied to troops. The only other type of small arms ammunition, other than the 6.5mm CTA round, and the 0.338″ (8.6mm) Sniper round, is the 9mm NATO round. This ammunition is supplied for use with the Glock17 Gen4 pistol issued for self-defence purposes. However, a pistol requires much practice to be accurate and has a maximum effective range of only 50 metres even in skilled hands. It has been shown, from experience with the Sterling Sub-Machinegun, that the NATO 9mm round can have a maximum effective range of 200 metres against soft targets in the right weapon. This is considered adequate for a Self Defence Weapon (SDW).

An outline specification for a suitable Self Defence Weapon (SDW) is proposed as follows:-

  1. THE ACTION. The SDW shall employ mechanically delayed blow-back action and fire from a closed bolt. The SDW action shall operate in the single shot, self loading mode only. (Automatic fire is not recommended for support troops who, as wartime experience has shown, can quickly exhaust their ammunition supplies, often for little effect.)    In order to achieve the required degree of accuracy and muzzle energy the SDW shall have a 15″ barrel, cold forged, with a chrome lining for long life and easy cleaning, chambered for the NATO 9mm round. The barrel shall be free-floating in the stock. (The above requirements are expected to result in a muzzle energy of at least 560 lbft, compared( with 420 lbft for a pistol; greater accuracy than a weapon firing from an open bolt, and much better accuracy than a pistol.) A small segment-shaped recess in the top of the receiver and the chamber of the barrel shall permit a visual examination to check if there is a round in the chamber. The SDW shall accept the British L3A1 socket bayonet.
  2. THE FURNITURE. The SDW shall be neat, uncluttered and easy to clean. The one piece stock shall be made of synthetic material that is resistant to abrasion, impact, oils, fuels, greases, acids, strong alkalis, moisture, UV light, high humidity and extremes of temperature between +50° and -30°C. The colour shall be Dark Earth matching the new MTP camouflage. The straight through butt stock shall be in line with the axis of the bore and shall be positioned so as to give a comfortable alignment of the eye with the sight line. The fore end shall cover the top of the barrel to prevent heat distortion of the line of sight. The fore end sides and bottom shall be parallel to the barrel and shall be drilled and tapped for the possible later fitting of Picatinny rails parallel to the barrel for accessories. It may be necessary to make the upper half of the fore end separate from the one piece stock, this is permissible. The SDW shall use the standard Glock17 pistol magazine holding 17 rounds. It shall be loaded into the weapon’s pistol grip. There shall be provision to attach a sling. There shall be storage for an oil bottle and cleaning kit.
  3. THE CONTROLS. A manual cross bolt safety-catch shall be fitted above the pistol grip. The trigger shall have a two-stage crisp action with a first stage pull weight of  5 to 8 lbs, with a second stage pull weight of 1 to 1.5lbs. Controls such as the safety-catch, magazine catch and cocking lever shall be capable of being operated by left or right handed operators or be readily interchangeable. The cartridge case ejection shall be clear of the operators face whether fired left or right handed. The trigger, safety-catch, magazine catch and cocking lever shall permit operation while wearing cold weather gloves. The magazine catch shall be positioned so as to avoid accidental release of the magazine.
  4. THE SIGHTS. The sight shall be a simple, low profile ‘Red Dot’ Non-Magnifying Reflector Sight, such as the Shield Close Quarters Battle (CQB) sight already in service. It shall be mounted on a Picatinny rail on the top of the receiver, (not the fore end of the stock). In case the reflector sight fails, the weapon shall have a V-shaped rear sight built into the top of the CQB sight and a ‘flip-up’ blade foresight, factory zeroed to 100m.
  5. THE DIMENSIONS. The dimensions of the SDW shall be as follows. The length of pull from butt to trigger shall be 15″ (380mm). The fore end shall extend at least 10″ forward from the trigger. The overall length of the SDW shall be not more than 30″ (762mm). The maximum weight with a Red Dot Sight, loaded magazine and sling attached shall be not more than 6lb (2.7kg).
  6. THE ACCESSORIES. The following Accessories shall be supplied with each SDW, A Blank Firing Attachment, a Blank Rounds Magazine, an Adjustable Sling, an Oil Bottle, Cleaning Gear, Four Glock 17 magazines in two twin Carrying Pouches with belt loops, and an L3A1 Socket Bayonet and Sheath.
  7. RELIABILITY. The SDW shall operate reliably when subjected to appropriate MOD tests for resistance to sand, mud, rain, immersion in salt water, snow, and temperatures between +50° and -20°C, plus drop tests, cook-off tests, etc. The SDW shall achieve an average reliability of 25,000 mean rounds between failures.
  8. MAINTAINABILITY. Field strip, cleaning and re-assembly of the SDW shall be straightforward with no tools required. Securing pins shall be captive to avoid loss. Complete strip, refurbishment and re-assembly by armourers shall not require the use of special-to-type gauges or tools.
  9. PERFORMANCE. The SDW shall be able to put 6 consecutive shots into a 12″ square at 100m. The SDW shall have a maximum effective range of 200m against soft targets.
  10. SILENCED VERSION. Because the 9mm round is subsonic the weapon lends itself to silenced operation by special forces. A limited number of the SDWs shall be produced with the following changes. Provision shall be made to fit a screw-on silencer. A raised threaded portion shall be machined on the barrel instead of the facility to fit the L3A1 bayonet. (The weapon may exceed the overall length of 30″ when the silencer is fitted.) A catch shall be fitted that will prevent blow-back cartridge ejection and reloading occurring on firing, resulting in quiet operation. Ejection and reloading shall then be carried out manually, at a time convenient to the operator by pressing the catch down and using the cocking lever. It shall be possible to operate the catch without taking the hand off the pistol grip. Holding the catch down while pressing the trigger will result in a normal single shot, semi-automatic fire taking place. A night sight shall be supplied instead of the Red Dot sight.
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64 Responses

  1. Good post, makes a lot of sense; I would specifiy ballistic performance rather than a calibre at this stage although I recognise that the US 6,5mm CT ammunition programme presents a bit of a fait accompli… my only quibble is with using 9mm Parabellum for a self-defence weapons for support troops. In my experience that was/is a totally useless round, not enough hitting power to stop anything. Why not keep the idea of a compact light weapon but give it a more useful capability, on the lines of the FN P90 or the Heckler & Koch MP7? As for the argument against another new calibre, just use the new weapon to replace the pistol for basically all pistol users; there are only a few special forces or police roles that would then demand a pistol and neither is likely to be a major logistics strain. Both are very compact and can be holstered next to the body, which would be ideal for AFV crews for example.

  2. Quick question if i may. I saw no reference to tracer rounds. My understanding is that these have different flight characteristics, and burn out around 1000m making accurate fire above this range difficult. Will tracer rounds to be retained? Will they be improved/ re-engineered?

  3. An interesting read! I am particularly interested in the rifle and PDW parts of the piece. It seems to me that the CTA round will likely be polymer based in which case a traditional rotating bolt, closed bolt rifle may not be best suited. Similarly, I don’t feel we need to be wedded to the bullpup concept, while it does save length the concept has other drawbacks such as balance, weight and weight of trigger pull issued to be dealt with. I also feel a combined safety/fire selector would be a better option than a separate cross bolt safety like the L85s’s. A 20 round magazine would also be a retroactive move, a minimum of 25 rounds would be better. Grippod too are cumbersome and the concept could be refined.

    As for the SDW concept, a 9x19mm pistol calibre carbine seems like a sensible choice but 9x19mm by 2030 is likely to be insufficient against proliferated combat armour- a concern of NATO’s now for more than 30 years. A more effective chambering wil probably be required. The use of Glock 17 magazines would certainly help logistics and are proven reliable. It strikes me a weapon of this size, calibre and intended purpose might also have a folding stock or action to enable greater flexibility. Just some thoughts.

  4. Overall a knowledgeable and thought-provoking article. Just a few nitpicks plus one substantive comment.
    * In the intro, the German 7.92mm Kurz bullet weight would have been 123 grains, not grams!
    * Under 6.5mm CTA para 3 he says one 7.62mm rd weighs 25.4g so one Kg = 280 rds; one 6.5mm rd to weigh 15g so one Kg =475 rds. Both are out by a factor of about 7.1. I think he means 10Kg in magazines.
    * Under FBAR para 3 and FGPMG para 5 the first and second stage trigger pull weights are surely the wrong way round.

    My main concern is over his definition of a requirement for an SDW, defined it seems by capbadge. The Taliban were no respecters of capbadge, and “support troops”, whether or not embedded with combat units, often had to do more than defend themselves at close quarters. This is a dangerous argument that bean-counters could latch on to. He claims that the Sterling SMG had a “maximum effective range” of 200m, but quoted (4th para after the video clip) the 5.56mm round in SA80 as having inadequate “stopping power” at 150m or less. What will be the “stopping power” range of an SDW with 9mm – 25m? (Maybe that’s why the bayonet is specified?)
    Also, is not the opening statement that the FBAR will require “extensive periods of training and practice” a weakness? Should not ease of training, including simulation, be part of the requirement? Regular “support troops” might have more training opportunities than infantry reservists. In terms of expertise with SA80, look at recent Army 100 and Methuen Trophy results at Bisley. There might indeed be a requirement for a “son of Sterling”, including perhaps in part of the carbine role he defines, but not on the basis he suggests.

  5. As a very long time user of the old Sterling SMG, I like the absence of full automatic, the closed bolt position and the idea of the magazine in the pistol grip, may I also ask
    1 that the cocking lever on the self defence weapon be a folding one that does not reciprocate.
    2 Why not a folding stock like the SMG
    3 What about a fore grip.

    Otherwise power to your elbow.

    PS I presume there would be a self loading but not automatic rifle GP for cadets.

  6. Having fired British, Belgian, Russian, Israeli,South African, and Rhodesian weapons in the bush and on the range, I have to admit that on patrol the best weapon to have is the MAG. Very comfortable to carry and extremely lethal.
    The tactics of shooting wildly when in contact dictate the carrying of massive amounts of ammo – disciplined fire with a NATO 7,62 round is more effective and therefore needs far fewer rounds than 5,56mm round. The heavy-barreled FN is also useful in this role and has the quick-change barrel. For short-range actions, the UZI (or its Rhodesian equivalent) is a beautiful weapon but, like most weapons shoots all over the place if fired in the automatic role. I have never found a situation where automatic fire was needed or wanted – even the MAG was fired in 2 – 3 round bursts. If you’re in a fixed position, then obviously a 0,3″ or 0,5″ Browning are most effective. While the AK is a brilliant weapon, I knew several people who had been hit with its weaker-force round and survived quite easily, whereas the NATO 7,62 was normally fatal if hitting the trunk.

  7. My 2¢ worth are as follows:

    “The Textron Company has, on behalf of the US Army, spent ten years developing 6.5mm(.266″) Cased Telescopic (6.5mm CTA) rounds which are reaching maturity.”

    The Textron system, developed over the last 10 years, will probably require another 15 years before it has the possibility to become accepted. Their system has all of the mechanical attractiveness of a 1950’s Singer sewing machine.

    Apparently; clearing a jam is non-trivial.

    The use of a polymer cartridge casing, particularly in adverse conditions, is still, apparently, not wholly proven and consequently, I don’t see this technology as; “reaching maturity.”

    In the mean time; Shell Shock Technologies have developed and proven their NAS hybrid case concept, that also enables significant weight savings and the elimination of brass. Do we need polymer cases with all of the associated problems?

    With regard to:
    “Some of these shortcomings can be addressed in the near term and the most likely changes will be:-
    The imminent introduction of the steel-tipped, copper cored, US developed M855A1 5.56mm and M80A1 7.62mm Enhanced Performance Rounds or a similar British equivalent round.”

    This is somewhat confusing, as my understanding was that the; ‘British equivalent,’ was already in place, but not as a; “steel-tipped, copper cored,” projectile.
    The M855A1 ‘steel-tipped’ concept has, apparently, not been accepted fully by Europe.

    Perhaps our biggest need will be the penetration of improving body armor. The race between armor and penetration appears to be in full swing.

    This subject of small arms, has, in many ways, been; ‘beaten-to-death,’ on The Firearm Blog (TFB) over the last few years. If you have the interest and three or four hours to spare, there are many views and opinions available there.

    There may, of course, be developments that are not available to read about……..hence my liberal use of the term; ‘apparently.’

    It’s always possible that there might be……….’jam tomorrow.’

  8. I’d start with acknowledging that requirements are hard.
    These aren’t great, even so. Lots of solutionising, lots of buzzwords and trendy terms where they really aren’t appropriate.
    CT cartridges in a reciprocating action? No CT system at present does, for good reason: the advantages of CT cases are based on not being a conventional cartridge. CT means you can make the cartridge a right cylinder. Right cylinder means that you can push-through, push-through means you can use weaker, lighter materials.
    3D printing on a mass-production item? Not playing to the advantages of the technology – you can use 3D printing to iterate designs without tooling costs, but mass production technology like injection moulding or extrusion is cheaper, stronger, faster and cheaper.
    Do you want to use the existing bayonet? Why?

    The bullet will not fragment at any range? How on earth do you ensure that?

    Mix and match imperial and SI units? (1.356J is 1ftlb)

    There are nice ideas in there, but there are some dodgy ones too.

  9. I would agree with Frank Morelli on the rifle/GPMG round should be chosen on ballistic performance at the designated ranges rather than specifiying the 6.5mm CTA (as hugely promising as it is) .
    As a gun’s design comes from the round selected outwards this must be given absolute priority and there is no lack of pundits out there with their choice ( millions and millions of them!)
    P.S. as the French have selected the HK416F in 5.56 NATO as their new battle rifle and a shorter barrelled version for support troops etc and spare ammo can be pushed their way!
    The USMC with the HK416 have adopted it as the M27 as well as the Norwegians adopting it as their battle rifle so they are in good company.

  10. Just to point out, 5.56 can be lethal at 1.2km too. The problem with it is not the lethality but tactics and accuracy. The 1.2km range is used for ‘area fire’ where you use the LMG to generate a ‘beaten zone’ of lethality. The real problem is that this tactic has fallen out of favour and is no longer taught due to the excessive ammo consumption the semi-random firing requires. The impliction of this is that the 5.56 really isn’t ‘underranged’, the limiting factor is more human limits in vision and generating the accuracy needed to hit at ranges beyond 400m. A properly scoped 5.56 weapon with a good shooter will still put someone out of action at 1km ranges. If you can hit. From range work, I have seen that it’s a near miracle if someone could get 50% hits even at 300m with all the running around.

    The US lines of research into things like the LSAT should not be seen as an attempt to get new CTA ammo or weapons into service but a self-perpetuating research program designed to keep the researchers employed until retirement. Don’t expect anything from them. Textron is just ‘riding the wave’ of popularity from the LSAT when it did their own CTA. the fad will die out soon. Or we will, long before anything comes out of those projects.

    20mm grenades…what to say… the 20/25mm grenade (XM-25) was simply an attempt to salvage anything from the failed OICW project, it’s also a dead end.

    Ammo weight, it’s sort of a contradiction if you know how much I’ve been complaining about soldier pack weights in past posts but I seriously don’t think it matters much. I’ve never known any incident of a soldier complaining about the weight of individual bullets and how they’re carried in the Load Bearing Vests or webbing ensures that a soldier almost never feels their weight.

    Like mr fred, my view on this post is similar to his in being a mixed bag of interesting ideas mixed in with dodgy ones along with a ‘techno-centric’ focus on numbers and not usage.

    Personally, I’d just go for an updated Ultimax. Why fix something that isn’t broken? The ones we have are getting long in the tooth and reliability is dropping. Age matters.

    Wonder if the ‘range problem’ could be solved by bringing back ammo carriers and using area fire like the MGs of old? Something to think about.


    I carried the MAG on a route march once. Never again if I had the choice. lol.

  11. I admit I did not have time to read the whole thing yet, but I stumbled here:
    “The recoil energy per round shall not exceed 10 Joules.”

    Recoil energy isn’t interesting. What matters is the impulse, not energy. This reminds me of Stan Crist’s case for what he thought was an optimal 6 mm round – he had a basic misunderstanding of physics, thinking he could understand recoil by looking at energy.
    You got to look at impulse, momentum. This is important because velocity has much less effect on it compared to work, energy. This helps to appreciate why lighter bullets mean so much less recoil effect.

    Besides that, I think “10 Joules” is a typo anyway. A 5.56 bullet has about 1,700 Joules muzzle energy, and the venting propellant gasses add more muzzle energy to this (the latter can be reduced by a muzzle brake by up to ~70%). There’s no way a useful firearm could have a recoil energy of under 10 J unless I misunderstood something really badly.

  12. S O, I think that you are misunderstanding.
    Momentum is conserved and linearly related to mass and velocity, so from starting at rest a 4g bullet is accelerated to 1000m/s one way, and a 4kg rifle will be accelerated to 1m/s the other, being 1000 times heavier. Energy is related linearly to mass and with the square of velocity, so the bullet has 2000J and the rifle has 2J.

    Neglecting propellant gases etc., but it shows the maths.

  13. Recoil energy (free recoil) is the KE that the gun has after conserving momentum over the gun, charge and bullet.

    10 Joules is relatively comfortable :-)

  14. 1 joule is one kg meter per second so it is a unit of momentum. A 70kg man would move 12.5cm in one second if worked on by 10 joules, very mild.

    …must…resist..posting…Ultimax Saw…. video….


  15. Observer, 1 joule is energy and is 1 Newton metre, or about 0.1 kilogram metre squared per second squared.

    Momentum is kilogram metres per second.

  16. momentum SI unit is kg*m/s

    energy SI unit is kg*(m/s)^2 = Joule

    Joule indicates the author thought about energy. He also wrote “recoil energy” in the text. Again, when it comes to recoil of small arms one should think of momentum and set a momentum SI unit as criterion.

    To think about recoil energy makes sense if you design recuperators or other springs that store recoil energy for later use.

  17. Since energy is force times distance, it seems as good a measurement for recoil as any, as it accounts for the mass of the weapon in a way that momentum does not. It can describe why shooting a light weapon is less pleasant than shooting a heavier one with a given ammunition.

    A shooters shoulder can be looked upon as a spring that absorbs recoil.

  18. Oops, my bad, I used the formula for torque not linear force. That’s the problem when you last touched physics 30 years ago.

    Can we just agree that the author simply intends to propose a low recoil weapon and ammunition and bypass the little nitpicking? I don’t see how being a pedant would help show the pros and cons of this proposal other than to sidetrack it into details that distract from the main points.

    One thing I would love to know is if there has been any improvement in propellant. Improved propellant would be an easy way to get some improvement ‘for free’ without the need to change bullet dimensions since all the change is ‘inside’.

    A more energetic propellant also has the potential to go in reverse, maintaining the same performance level while reducing the size of the casing itself, allowing you to carry more. An extreme imagining of the concept would be something like 5.56 rounds which look like blunt pencils without the tapering from the case to the ball. How many rounds could you put into a mag if the maximum diameter of the round was simply 5.56mm or even 5.7-5.8mm in diameter instead of the 10?mm base diameter rounds used currently? Though with the change in round size. you’re unfortunately going to have to rechamber all your rifles, which is not a casual task for a large army.

  19. The most efficient shape in terms of surface to volume area is a sphere. The farther you go away from that, the more weight for casing you have for a given volume (propellant power).
    A thinner case would be less weigh-efficient than a fat one. The current cases are compromises between box/curved magazine capacity and case weights (on top of that there are some considerations regarding internal mechanics that lead to certain neck angles).

    A possibility would be to go to a shorter case as with the 5.56×30 MARS project if you have great propellant improvements or think you can make do with less power, though.

    Hotter loads may necessitate thicker shell walls at least for use in certain guns, of course.

    BTW, I don’t think the remark about momentum was pedantic. The criterion used by author is a wrong one for the purpose. It could lead to incorrect preferences or choices. This is particularly noteworthy because hardly anyone ever discusses recoil with units in public. Sadly, whenever it’s done in regard to small arms the author appears to get the physics wrong (hence my remark about Stan Crist), which is misinforming the readership.

  20. SO, I think you confused bullet -shape- and case wall thickness. You can have the same thickness of wall but a different shape, not to mention the sphere is utterly the wrong shape to use in a bullet casing since it also takes up the most *volume*, not something you want in a magazine. If the 5.56 was spherical in shape with a bullet plugged in one end, I very, very severely doubt you can load 30 rounds in.

    As for the correct SI units, I have to point out you’re not improving the discussion as much as you think. As long as people get the right criteria, does it matter? In fact, I’d say it’s better for people to get the wrong criteria than to derail the topic in the first place! At least with the wrong criteria, you’re still on the topic rather than have it devolve to discussions on SI units which is what is happening now.

  21. Observer, in terms of internal volume to wall ratio, S O is correct that, in the limit, a sphere is most efficient, so the further you go from that ideal will incur a parasitic weight penalty. However, one must also accommodate your point that thinner means more rounds can be laid alongside each other in a given space.

    S O,
    Energy is an entirely appropriate term to use for defining the free recoil of a rifle. If you use it to specify recoil of ammunition, as done here, then it is meaningless because it requires the weight of the rifle to calculate.

    To carry on ragging on the article*, the temperature range is short as storage temperatures can go up to +71 degrees C. Also, if you are specifying Picatinny rails, do you need to specify what goes on them? Wouldn’t that be the subject of a different procurement excercise?

    *to the author: I don’t mean all this as a personal attack. I appreciate the time and effort required to put these articles together and the confidence required to put it out in the public domain. The comments may seem harsh, but stimulating a debate is useful too.

  22. Thanks for taking the time and effort, it takes a brave person to put their thoughts out into the ether.

    I have a couple of questions in regard to your Outline Self Defence Weapon (SDW) Requirement for Support Troops.

    Your article states that you require a carbine version of the standard rifle for use by weapons crews, air crew etc which helps with commonality and traing etc and as the weapon has a low felt recoil to begin with and will be fired in the same manner as a rifle both of which will help an inexperienced shooter under stress, especially considering your 100m to 200m (?)range is the the SDW required?

    In terms of commonality is adding another weapon to the logistics and training system in 9mm really worth the squeeze over an in service pistol?

  23. Quick note about recoil energy:

    I’m pretty glad it is stated as energy rather than momentum. The reason being that it is the energy you soak up in your muscle and bone structure.

    The best way to think about it is to consider a 10g bullet shot at 1000 m/s. It has a momentum of 10 kg.m/s. Now consider a 1kg brick thrown at 10 m/s. This has EXACTLY the same momentum and will knock you back at the same speed, but has only 1% of the kinetic energy that you need to soak up in your Kevlar vest or riot shield.

  24. Come to think of it, has any armed forces bought into the PDW concept? If I recall correctly the PDW fad was just a passing phase with very little pick up from armies around the world but found some purchase in police and special operations groups, a very niche market. From memory, the only 2 notable holdovers from this period are the MP7 and the P-90. Sure, people still design PDWs but sales are few and far between.

  25. The biggest application of the PDW concept so far was the M1 Carbine of WW2.
    That was before the nonsensical CRISAT penetration requirement that brought us the SCHV generation of PDWs.

    There were some dedicated ‘rear area troops’ firearms that date back as far as the 18th century, so the idea that non-combat troops should have a lighter, less bulky and hopefully cheaper firearm is an old and likely sound one.

    BTW, once upon a time I wrote an entire website dedicated to PDWs only. Sadly it was somewhat obsolete a few years later due to munition developments.

  26. William Lyon,

    As the author of this post I would like to respond to the comments made below. First of all I should explain that I have never seen a shot fired in anger, but I once achieved my marksman’s badge, and once beat my CO in a pistol tile shoot, (not a good career move). The post came about when I was housebound following a hip operation and stumbled on several small arms websites which took my interest.

    I thought TD was very brave to publish it, as it is obvious that I have only a fairly sketchy idea of how the Army operates. I was very pleased to see it quite well received and very impressed by the quality of the comments.

    Yes, some of the comments were harsh, scathing even, but no worse than I expected as an amateur straying into the domain of professionals. I realise now that this subject has been ‘beaten to death’, so lets hope that MOD(PE) come to some timely conclusions and shut us all up; although in my experience they live in the confident expectation that a cheaper more efficient solution is just around the corner if only they wait. And now to respond in detail to some of the comments.

    “I would specify ballistic performance rather than a calibre at this stage”

    Agreed, there I go ‘solutionising’ again. I fact I did both, the ballistic performances appear further on.

    “My only quibble is with using 9mm parabellum for a self defence ….it is a totally useless round”
    “My main concern is over his definition for an SDW, defined it seems by capbadge”
    “9x19mm by 2030 is likely to be insufficient against proliferated combat armour”
    “Your article states that a carbine version of the standard rifle ………has a low felt recoil………….is this the SDW required?”

    Well I got that one wrong then. Delete Annex D. I assume that a lighter and hopefully cheaper Self Defence Weapon is still required for support troops, however you define them. Perhaps Annex B Para10 should read;

    “10. CARBINE VERSION. A Carbine version with an overall length not exceeding 22″ and using as many components as possible of the FBAR shall be introduced for use by troops requiring a more compact weapon for operational or self defence purposes. The Self Defence (and Army Cadet) version shall be single shot self loading only and normally fitted with a simple red dot sight.”

    As 9mm x19 is considered as not very effective where does this leave Pistols?

    I would be interested to know how often pistols were actually fired in anger in the various post war campaigns. I can find nothing on the internet. Any ideas? I know from experience that even in range conditions it takes plenty of practice to reliably hit a target at much more than about 10m. How accurate it is in action conditions I can only guess.

    “A combined safety/fire selector would be better than a separate cross bolt safety”

    I have read several conflicting views on this. One school says a three position lever could be confusing in the heat of battle and the other is all for it. I guess the only way to resolve it would be to ask 500 infantry NCOs for their views and go with the majority.

    “The CTA round…polymer based…a traditional rotating bolt, closed bolt rifle, may not be best suited.”
    “Apparently clearing a jam is non trivial…………..The use of a polymer cartridge casing is still apparently not wholly proven.”
    “CT cartridges in a reciprocating action? No CT system at present does.”

    So the CTA round is not as advanced as the Textron web site would have us believe, but will it be right by 2035? I have no knowledge of how CTA actions work, so I shouldn’t have gone down that route.

    “The bullet will not fragment at any range”
    Perhaps this should have read “The bullet shall not be designed to fragment ”

    “No reference to tracer rounds”
    Oops. Of course any spec for ammunition should include the requirements for Ball, Tracer, Armour Piercing etc.

    “Recoil energy per round shall not exceed 10 Joules”
    I was intrigued to read the discussions that this provoked. In my defence the figure came from a website which compared the weapon recoil energy of the 6.5CTA at 10 Joules with 7.62 NATO at 17 Joules. I did my O level physics in 1952. Lost track of things a bit since then.

    “A 20 round magazine would be a retroactive move”
    I should have said ” The magazine shall be the maximum length that will not strike the ground when the rifle is fired in the prone position” Only further development would show how many rounds it will hold.

    “Do you want to use the existing Bayonet. Why?”
    Why not? Is there something wrong with it? Why not save money by using what we already have.

    I could go on. Thank you ‘dhooghe’ for the pointer to the shellshock technologies website.

    I have achieved my aim, which was to stave of boredom while housebound, with the added bonus of provoking discussion on Think Defence. This was more than I dared hope for and I shall now withdraw.

  27. Just to query, isn’t bullet fragmentation a good thing? One of the theorised reasons for the complaints in the lack of lethality for the new SS109 round was the removal of the cannelure which in the old M183 round usually fragmented and caused further injury. This is in addition to the lower velocity from carbine barrel length weapons further reduced the wounding capability of the round due to lack of yaw.

    Regarding bayonets, as much as I loved mine, and I really do miss the usefulness when you need to cut things like comms cord, it’s found that these days, the ‘up and at them’ tactic is very, very rarely performed, most people being content to stand off and snipe/shell/bomb their enemies to death without closing in and for the incidents that do involve in ranges where you can reach out and touch someone, shooting the bugger works just as well, hence the decline in the usage of bayonets in the present time. Worst case, you can always buttstroke the fellow. Nostalgia and paranoia tells me to keep the bayonet, logic tells me to let it go. Such is life.

    One old and still favoured idea of mine is to have a common family of weapons derived from the Ultimax saw. This is in part due to its mostly modular architecture. Since it has a QCB and a functionally useless stock that can be removed, the difficulty in swapping in a short barrel and a wire/extendible stock is negligible. The weapon is mostly hollow and skeletonized, the frame is simply a scaffolding to hold the barrel and bolt carrier group together.

    Replace/remove the buttstock, swap with a short barrel, you end up with something like a 5.56 SMG.

    This guy is using a short barrel fit, something I would call a ‘carbine’ version.

    Functionally, it works like this

    Personally, I foresee a new manufacturing coming soon for the U-100, the ones we have are getting old and worn out. High time too.

  28. The Ultimax 100 and other really lightweight 5.56 LMGs never seem to make a breakthrough, and usually don’t fare well in competitive tests by large armed forces.

    The KAC Stoner X-LMG / KAC Light Assault Machine Gun is another such case. The basic design is older than I am (based on Stoner 63), includes constant recoil as does the Ultimax 100, has been worked on again and again and it’s even below 4 kg weight now with belt feed, but there’s no real sales progress AFAIK.

    Imagine this: An infantry with 50% of men equipped with a 5.56 mm LMG with bipod, Aimpoint CompM3 and 150 rds belt bag. M855A1 with fluorescent base and 25% lighter cases, two reserve bags per gunner and some crossloaded bags in the squad.

  29. The U-100 is actually quite decent, carried one in basic. Not sure of the rest since I never hands on with them before. It does have some decent sales numbers but ST Kinetics believes in operating ‘black’ so you won’t get public disclosure of buyers but there were some, you just need to find them online, for example Sri Lanka, Croatia, Indonesia etc. You need to work to find the buyers.

    It’s old and hence it has some ‘old’ concept quirks that were inherited which I find interesting and useful. The rear sight can be flipped up to convert it into a long ranged sight, it’s gradated to a max of 1200m, a holdover from the old area fire MG tactic. One of the gas port settings is also a ‘blank’, i.e it does not cycle the bolt. It was supposed to be for use with bullet trap rifle grenades. Even the ‘removable buttstock’ was a holdover from the old ‘fire from inside APCs’ concept which died out decades ago with internal firing ports. Irony of it is that the old holdovers from the past created a very flexible system that is quite useful even now.

  30. My question on the bayonet really goes down the route of optimisation, and what the primary function is. The current bayonet is primarily a bayonet. The attachment method offsets the blade and it’s cast steel, not forged. As a result, you get soldiers carrying a knife as well. Looking at the Polish Grot rifle, which I admire, they have gone down the route that the bayonet is primarily a utility knife that you can attach to the rifle.

    Also a bayonet that you attach to a free floated barrel is going to play merry hell with the barrel harmonics.

  31. Janes, July 2016, said the Americans had fallback , conventional rounds in development, the .264 USA & the .277 USA, if the polymer CT rounds were too far away in development.
    On the PDW, I think .357 Sig & 10mm auto (which replicate the ballistics of the .357 &.41 magnum revolver rounds) are more use than the exotic 4.7/5.7 rounds that have proved no more effective than the .22 WinMag rimfire round.
    I must admit, I would like to see an Ultimax in a more effective round, say either of the .264 or .277 USA rounds.

  32. I suppose bayonets make sense for MP (riot/crowd control), and those dudes in parade uniform who greet foreign politicians at airports, but nobody else.

    There were some dual calibre firearms – an optional “silenced” .45ACP pistol mounted where sometimes UBGL is mounted would add some of the functionality of a bayonet.

    I remember that some successful Allied mass nighttime assaults in Italy were done with bayonets attached and hand grenades, but rifles unloaded. This was meant to and did) prevent nervous 18 -20 year olds from firing treacherous shots before the assault was within hand grenade range. Even hand grenades did not necessarily betray the attack because some mortars dropped HE at the time (as at other times, for desensitization) to offer background noises.

    Well, nowadays you could have that bayonet replaced with a subsonic bullet “silenced” weapon (captive piston with electric priming would be better, but you can’t have all nice things).

  33. The Grot’s a new one on me, had to go read it up.

    mr fred, do you really want to open a can of food with something you might have just stuck in someone? lol.

    On the topic of ‘future small arms’ I strongly suspect there isn’t going to be any new innovations to be had for the foreseeable future, most new ‘research’ projects didn’t go anywhere, so we’re stuck with the same old 5.56, 5.45 and 7.62 for now, which means any new small arms would simply just be reiterations of older weapons instead of something groundbreaking since there hasn’t really been anything to cause a paradigm change.

  34. A possible paradigm change would be if one would
    – move towards a powered (and communication) NATO rail with a central battery in the grip as standard
    – dial back the accessories fashion
    – dial back the Afghan mountains-inspired attention on range
    – focus on light weight for real
    – move towards great AP capability because body armour becomes less burdensome (possible if exoskeletons have a breakthrough, possibly even with unpowered load-bearing exoskeletons)

  35. William Lyon

    ‘with the added bonus of provoking discussion on Think Defence’

    Which is always interesting.


    I think the PDW nether took hold purely due to the fact that when most of NATO changed to the 5.56mm intermediate round the cost/benefit of having PDW’s rather than carbines just wasn’t worth it.

    Most armies used the 5.56mm to replace both thier battle rifles and SMG’s due to the round being more controlable (over a full power round) for the less experienced shooter and giving more reach than a pistol cartridge.

    The bayonet is also a psychological tool if you’ve fixed bayonets prior to launching an assault onto an enemy position you are put into the mindset of having to engage in close combat. It’s also one of those subjects where as many will agree as dissagree to it’s use in modern combat and as they don’t exactly cost a lot in maintenance what is the harm.

    Should they be made more utilitarian in this day and age? Probably.

  36. The Grot, formerly known as the MSBS, looks like a really well engineered system. I did see rumours that the manufacturer was looking at a 7.62mm version, which would allow adaptation to one of the fallback 6.5mm rounds the US is looking at.

    I’d be likely to use a knife I’d used to open my dinner to stick an enemy, and it seems to me that that would be the sensible way around. If you consider bayonets important or not, a utility knife that can be used as a bayonet is a better than a knife and a bayonet or just a knife that can’t be used as a bayonet.

    As for paradigm changes, they seem to be the enemy of actually getting better stuff.

  37. DN, I think the problem has more to do with the concept of the PDW than the effectiveness of the round. The goal of the PDW was a ‘convenient weapon for support troops’ but let us just put it this way, if you’re a lazy loggy used to running around ‘clean fatigues’, carrying a PDW is just as annoying and troublesome as carrying a carbine since you’re used to carrying nothing at all. Really lazy ones just leave the weapon in the truck/track/car, which won’t matter if it’s a PDW, carbine or even a full heavy machine gun since he ain’t carrying it.

    For those who do carry as good practice, a slung PDW isn’t much different from a slung carbine in terms of ergonomics and weight, the P-90 isn’t markedly different weight wise from a clean M-4.
    This is further exacerbated by the fact that most loggy vehicles come with machine guns. Why bother using your personal weapon when you got an all up GPMG you can use? I even remember an exercise passed down by word of mouth where a quick thinking driver put an entire platoon of Commandos into weekend confinement when he MILESed the whole lot of them during a simulated overrun attack with his vehicle GPMG, caught them all out in the open. Apparently, he didn’t bother with short bursts and just hosed the whole lot of them with every round in the box. The ones confined were cursing the ‘genius’ very openly, which was how it became so well known.

    In short, the PDW was an interesting concept that sounded nice ‘lighter weapon for support troops’ but in practice, there was no real need for the weapon. Hell, I don’t even remember our support troops ever even having SMGs, only carbines or ARs, so no SMG replacement. Nice in theory, unneeded in practice.

  38. mr.fred
    “the comments may seem harsh but stimulating a debate is useful too.”

    Agree entirely, no offence taken, speak as you find and stimulate the debate.
    I shall wait to see if there are any more comments and then for my own amusement I shall rewrite the whole thing, but it would be unfair on TD to ask him to publish it.

  39. This could turn out to be an interesting review of how to write requirements, so TD could perhaps run with it in that direction.

    I’ll add a couple of thoughts, some to elucidate previous points and some as other areas to look at.

    Cased telescopic systems are almost always push-through systems, so the spent case is ejected from the chamber by the next case being fed in. This means that the chamber must be moved out line with the barrel. By using this mechanism, the case does not have to be as strong as conventional cases that are pulled out of the chamber by a small extractor claw, so the CT cases can be weaker and, more importantly, lighter. Though there are also developments with conventional cases that make them lighter than brass.

    The US are also working on a 6.5mm conventional cartridge called the Creedmoor, which might be worth a look, though it’s closer to 7.62mm NATO than it is to being in the middle of the former and the 5.56mm NATO, and there’s a cartridge closer to the latter, called the .224 Valkyrie. Or you could spec your own, just remember that recoil energy is dependent on the weight of the rifle.

    I’d also recommend looking at the Polish FBRadom Grot rifle system. Were it my call, I’d buy a gross lot of them in all the different configurations and give them a damn good testing to work out what the optimum configuration is.

    There does seem to be some interest in using suppressors for all infantry weapons at the moment. Might be worth considering.

  40. My personal opinion of the wish for increasing ball sizes from 6.5-6.8mm is that it might stem from the impression of ‘bigger number=better’. If that were the case, the Tokarev pistol would have been an assault rifle (7.62mm). These ‘improvements’ are unnecessary as a redesign of 5.56 could have the same effects without the need for wholesale replacement and/or rechambering of a whole army’s weapons.

    An extreme example without consideration of legality would be something like making hollow point 5.56s or adjusting the weight distribution of the round to increase likelihood of it ‘tumbling’ upon impact or structurally weakening the round by cutting cannulures (I know, not the ‘proper’ use for cannulure). Increased penetration could be had by steel or tungsten core copper jacketed/cupped rounds etc. Please note these are -examples- of how there is a lot of scope for round redesign, NOT suggestions for how a new round should be, if it were, I’d just check myself in to the nearest mental institute. A 5.56 round redesign is overdue IMO, especially with the sudden shift to carbine length barrels which no one anticipated (I sure didn’t, thought they would keep the M-16s) and shortened barrels which were rumoured to negatively affect round performance, any new round would have to be optimized for carbine usage in the future.

    mr fred, I prefer just using earplugs. You can still hear perfectly well with them while they cut out high pitched/high volume noise. I hesitate to add anything to my rifle that might affect the ballistics of the round especially since I already got used to certain offset lengths. God knows where my round will end up with a can plugged to the end of my barrel. To hit a Fig 15 at 300m/330 yards, you need to aim somewhere around standing lower hip level for a 5.56 rifle zeroed at 100m, I’ve no idea where to aim with a silencer, so I’d rather adjust the shooter (especially since a pair of earplugs don’t affect ballistic or shooter performance). Or maybe I’m just too much of a purist.

    One thing I did notice regarding equipment requirements is that the focus on technical details is too narrow. This works sometimes for fixed equipment where all you have to consider is performance but for ‘flexible use’ items, it becomes very limiting. Maybe it’s because of my experiences with the Ultimax but it is a very strong example of how ‘numbers don’t tell everything’ and if forced or shoehorned into a very limiting role due to limited technical specifications, the potential for the item is lost in the paperwork (IAR anyone? lol).

    A more flexible approach might be to give either a scenario/problem or a concept of operations and ask designers to compete with each other for a solution. This helps in that it forces the supplier to actually think of how their weapon is supposed to be used and avoid situations like the US’s LCS problem where they got the equipment but no idea how to integrate it into their fleet. It might even cause cases of new approaches to old problems rather than rigidly following old tactics that new equipment might have made less efficient.

    Now all I have to do is to figure out how to drop a suggestion for a VLS tank for the US’s MPF program. ;)

  41. The suppressors in the tests I’ve read about have been permanent fit, so the reticle, sight adjustment and any aiming offsets would exist for the suppressed rifle and you’d be complaining about taking the suppressor off as it would change your point of impact.

    The suppressors are not just for the firer and his comrades, it also reduces the ability of the opposing force to detect where he is shooting from.

  42. A quick note on the .264 & .277 USA cartridges.
    Up til now, any new rounds have been designed for 5.56 magazine wells. To get more performance in that short space, means a fatter case, reducing magazine capacity i.e. a 30 rd 5.56 magazine can only hold 26 6.5 Grendel or 6.8 rounds.
    With the .264 & .277 USA rounds, they went for a longer case that fits inside 7.62×51 magazine wells, but is slimmer than a 7.62 case. That means you get more rounds in a 7.62 magazine.

  43. Observer
    ” a redesign of 5.56 could have the same effects without the need for wholesale replacement and/or rechambering of a whole army’s weapons.”

    I wasn’t thinking of putting a new rounds into old weapons. I was thinking what do you do when all the SA80s and GPMGs are worn out and declared BER and you need to buy new weapons? Do you carry on as before with 5.56 and 7.62, or do you go back to the principles of 1954 with the 0.280 used in both the EM2 Assault rifle and Taden GPMG (which package wouldn’t look too out of date today) and take it from there. I think the latter makes more sense.

  44. Janes has an item from 27 March saying the US is starting trials that could lead to the replacement of SAW & M4 carbine. Their starting point is a 6.8mm round.

  45. JH, the US also had trials for light weight and caseless ammunition in the LSAT program up to readiness level 7, yet no sign of anything coming into service. They have a lot of these ‘trials’ that end up as nothing but data collection, no point reading too much into it. The US has way too many cancelled programs for anyone to be confident of anything coming out of them. Recreational shooters might have a fun time with them though, not being tied to slow and whimsical bureaucracy.

    mr fred, are they really that effective? I’ve often thought the ‘hide from enemy’ reasoning is more theoretical than practical since even suppressed, the muzzle blast is still very prominent on something with such high energy levels like an assault rifle and nothing is going to hide the crack/boom of the round going supersonic. Not to mention humans localize more by visual cues, sound just gives a general location to look and even suppressed, the sound levels are more than enough to give away your general location. Do suppressors really hide someone that effectively?

    William, if you want to go down that route, it is possible. You just have to consider the additional cost and time needed for the redesigns of the weapons, ammunition and troubleshooting a new weapon. Even the SA80 had teething problems at first. The L86 never really recovered from its teething problems, being replaced in role by the Minimi. When you do something totally new, the possibility of failure is there, though it isn’t as if it was not done before. The Russians introduced their 5.45mm with their AK-74s while the Chinese have their 5.8 QBZ-95s, so it’s not impossible, just costly, troublesome and a bit risky.

  46. Observer,
    The suppressors do nothing about the supersonic crack, but apparently hide the “thump” of the muzzle report, making it harder to locate the firer by sound.

  47. It is true that there have been many failed attempts to replace the 5.56 with a 6 to 7mm cartridge.
    This time I think it might happen, as the background noise is that the generals/politicians are scared that US “warfighters” no longer have the edge over the enemy.

  48. So, my two pennies worth. I am old enough to have trained on SLR / Sterling and the 7.62mm LMG version of the “Bren gun”. On my second time around in uniform it was SA80, and I was in a unit where we did maybe more than the normal amount of pistol work.

    So, I understand the fascination with range based on recent experience in Afghanistan, but don’t agree with the US obsessions of an infantry rifle that is lethally accurate out to 600 to 800m. All WW2 and Korean war studies suggest mountain ridge line to mountain ridge line “sniping” is somewhat of an aberration, and that in most infantry combat, MG and HE cause the casualties.

    Given all the comments on how long an intermediate caliber case telescoped system might take to come to fruition, perhaps we should just concentrate on defeating an enemy who might be better equipped than the Taliban , e.g. using body armour.

    So how about:
    1. Put 3x GPMG Light Role into a support section in each infantry platoon. Use all the modern tech currently being studied to reduce the weight of this weapon. Have it shoot CBJ Tech sub-calibre rounds for greater ballistic performance, range and penetration:×51-cbj/

    2. Commonality – Ditch further upgrades to the SA80 platform and dive into the Polish MSBS Grot “system”. One common weapon system in bullpup, or “conventional” layouts, in 5.56 NATO and soon in 7.62 NATO, so it could replace the L129 too.

    Pretty sure a short bullpup, or short carbine with folding stock would do for the “non-infantry” use cases!

    If you want to throw greater commonality to the wind, or just give to spec ops, you can also have this rifle in the .300 Blackout round, again using the CBJ Tech:

    3. Finally take on the idea that I think was first suggested by Tony on is site some years ago, replace all 9mm pistols and SMG’s with CBJ Tech 6.5mm because of it’s better performance against body armour:×25-cbj/

    So only changing the ammo for our 7.62 MG’s, a family / system of weapons for commonality at 5..56/7.62 (and / or .300 Blackout if required) – meaning if you do want a long ranged sniper competition in the mountains, your armouries can deploy more 7.62 designated marksman type rifles with greater ease. 9mm can be converted to shoot 6.5mm with just a barrel change.

    Use whatever case technology will provide reliable performance while reducing weight.

    Could keep us going without too much fuss until Plasma Pulse Blasters are invented !

  49. lol you wouldn’t happen to own shares in CBJ by any chance do you Jed?

    Interesting plan. We’ll see how the future goes, especially since there does not seem to be any immediate desire in the UK for a change of small arms as the SA80s are still relatively new. Remember though, it took about 10 years to for the British Army to completely change over to the SA80 series of weapons, expect the same time scale if you want to repeat the same event over again.

  50. You might want to look up the POF (Patriot Ordnance Factory) Revolution, billed as the most compact .308 AR ever made. Gas piston system. Same size as their .223 version. It is getting good write ups in the US gun press.
    A version of that in the new .264 & .277 USA rounds, would be quite a contender for future NATO adoption.

  51. Back to the Future, my understanding of the 7mmNATO -280/30

    The Wehrmacht developed the assault rifle during WW11 as they were being overwhelmed by the larger number of Soviet troops. German standard rifle/machine gun round was the rimless 7.92 x 57mm, recoil on full automatic fire with a rifle was too powerful to control, so they turned to the pre-war development of the Polte Madeburg arsenal, the 7.92 x 33mm Kurz (short), a cut down version of the standard round and so limited capacity for propellant and a lighter bullet, 125g, result substantially lower recoil, Hugo Schmiesser StG44 assault rifle developed enabling full controlled automatic fire, 426 thousand were manufactured, though never able to meet demand. The Soviets in response to the 7.92 Kurz came up with the 7.62 x 39mm round made famous with the AK47. The rounds were ballistic compromises necessitated by war to use the installed production machinery for the German cases, 7.92mm bullets and barrels and Soviet 7.62 respectively.

    Post war the British army set up a small arms committee chaired by the Dr Beeching, who had been seconded from ICI during the war, to find a replacement of the .303 round which dates back to 1888, originally as black powder rimmed case, earlier attempts to change had been thwarted by events. Aim was to replace the ancient 303 and based on the new paradigm shown possible by lower powered 7.92 Kurz and the 7.62×39 Soviet rounds to optimise its ballistic performance, as not constrained by wartime imperatives of using production machinery, to have a universal round, not as today with the 5.56 and 7.62.

    270 and 280 rounds were designed together in 1947, the 270 had a steel cored bullet diameter of 0.279 in. and weight of 100 grain with a MV of 2,750 -2,800 fps, rim diameter 0.445 in./11.3 mm, case length 1.81 in./46.00 mm, OAL 2.45 in / 62 mm, submitted June 1947 and dropped in favour of the 280 in 1948. Note the smaller the diameter of the round gives the advantage more rounds can be held in the magazine.

    Designed January 1947 with a rim diameter 0.4580 in. /11.63 mm a loading of 30.1 grains and a mild steel 130 grain bullet 0.284 in diameter at 2,450 fps (the same MV as the .303 Mk VII ball). The 280 calibre was slightly larger than originally intended but was selected to meet US desire for long range performance.

    The ADE re-engineered the 280 to the 280/30 in April 1948 to offer the same rim dimensions as the rimless US 30-06 & T65 (destined to become 7.62 NATO), rim 0.473 in/12.01 mm, case length 1.71 in/43.43 mm, OAL 2.54 in/64.52 mm with the eye on the possibility of being standardised by NATO.

    By November 1948 attention switched to a heavier 140 grain bullet to meet the US requirement for steel helmet penetration at 2,000 yards, muzzle velocity was 2,415 fps with 24.5 inch barrel (the longer length due to EM-2 rifle being a bullpup design), 30.5 grain charge and 21.5 tons/square inch pressure (48,000 psi).

    In 1949 the UK cooperated with Belgium/FN, whose engineers suggested use of the 7mm Mauser bullet type S12 with a CNCS envelope and a lead core 140 grain

    The NATO trials were held in 1950 at Fort Benning US, the 280/30 with EM-2 was pitted against the original T65 (7.62×47)/T25 rifle, the EM-2 fired 57,000 rounds, with the M1 Garand as control. The Trials Board reported “The T65 Cal. .30 is not satisfactory because of its excessive recoil, blast, flash and smoke, the Cal. 280 is not satisfactory because of its relatively high trajectory. That of the two basic types of rounds submitted for the test the British calibre .280 is preferred.”

    The result was rejected by the US Army Chief of Staff, nothing would do but a full powered .3 inch calibre, the 7.62 NATO was the US 30-06 cut back, a general had noticed on a visit to arsenal that they were not filling the case to capacity, would have ben too powerful even for the semi-automatic Garand.

    The 280/30 charge was increased to (?grains) 2,550 fps with the 140 grain bullet and adopted in 1951 as the 7mm Mk 1Z (Z nitocellulose powder). Recoil energy was 7.4 ft-lbf/10.0 J with EM-2 rifle, for comparison the .303 recoil energy was 11 ft-lbf with No.4 rifle and the 30-06 14.4 ft-lbf with the MI Garand.

    Manny Shinwell, Secretary of State for War, adopted the EM-2 rifle for Army and it was classified it as ‘Rifle, Automatic, Calibre .280 No.9 Mk1’ and the 280/30 cartridge 25th. April 1951. After the change in government Churchill rescinded Shinwell’s decision in the name of unity with US in early 1952.

  52. Isn’t the answer a 84mm recoilless rifle? The Taliban were not using AKs from beyond 600m.

  53. CarM, you didn’t happen to mistype your name and mean CarG instead do you? lol.
    As much as I love the Carl Gustav, and I do love it very much, it’s a heavy support weapon with limited ammo, the ‘carrier’ backpack only holds 4 rounds and it takes the place of your backpack. Not to mention with the normal sights, I doubt you can ‘tag’ someone past 400m, at that range, a person looks incredibly tiny with the naked eye and I don’t even know how you’re going to estimate droppage at that range.

    Love the idea of an explosive finish though. Just don’t know how practical it is to deliver it at 600m, the Carlie G was meant to be used for much larger targets.

    JH, I’ve been playing around with the idea of caseless lol. I got an idea for a basic mechanism that won’t look like someone’s pocket watch (H&K G-11) but it’ll be a long, long time before anything comes from it. It’s also limited since there is no way to get rid of excess heat so the only choice is to lower the ROF and allow some air cooling before a follow up shot so don’t expect a 900 rpm ROF like the M-16.

  54. Just to point out that the .264 & .277USA rounds are conventional brass, NOT caseless. They are designed to fit a 7.62×51 magazine well, but have a smaller diameter case head than the 7.62×51.

  55. … AND H&K got an order for an upgrade of SA80A2 to A3 standard (whatever that may be – my guess is more/NATO rails and M-LOK for more attachable Gucci gear).

  56. great blog, i think we should look st 5.7mm and 4.6mm for smg and pistol as both can peneration better than 9mm.

    as modern solider will carry better body armour which could stop immediately against 9mm.

    personally: would love see nato or british use;

    5.7mm for smg and pistol.
    6.5mm/7mm for assault rifle and light machine gun, dmr.
    8.6mm (. 338) sniper and heavy machine gun.

    primarily assault rifle design for fibua size as standard as ideal bullpup which suitable for royal marine and british regular for in mpav or apc, ifv vehicles and even combat in ship (royal marine) as it is good size barrel for engaging in cqb and distance.

    also make sure common part in assault rifle (conventional /folding) for parachute ((para)) and yet regular can operate it as it is also can benefit for in mpav and apc, ifv as well.

    ethier will be ok.

    also burst fire (3 rounds burst) is better optional including as it is usefully.

    short term we should look at hm416 or desert tech mdr.

  57. I’d keep the SMGs at 9mm…
    Remember, what are SMGs most often used for?
    Form follows function, sometimes you do NOT want more damage/penetration.

  58. With the phasing out of both the LSW and the LMG and the increasing number of 7.62mm rifles being used amongst infantry units there may be a drift towards the old mix of battle rifles and carbines/SMGs. But… we have the L85A2, and now the A3, which will be around for many years to come and will be the ‘carbine’ for a while.

    The idea of a SDW does rather appeal to me. I’m not an infantry type and having to manage an SA80 whilst also working is a pain.
    I’m thinking:
    Stick with 9mm? If we must.
    Fed by Glock magazines? I’m happy with that, but can we have some 33 rd mags too?
    In-line stock? Not sure we need that for a 9mm single shot.
    Bayonet? No thanks.
    15inch barrel? Does it need to be that long? Why not a bit shorter.
    Something along the lines of a Wilkinson Arms Linda 9mm Carbine.

    If the Russians can knock out the PPS43 in a few months within a besieged city, why could we not develop a pressed steel, Glock mag fed folding-stock carbine? Chuck a picatinny rail on the top between some basic iron sights and I’d be happy….. Except if I had to use it in anger, then I’d reach for the L85A2.

    But for now I appreciate both the L85A2 and the Glock 17, but having a few more 7.62mm weapons, especially DMRs, available would be very handy.

  59. Well if I was designing my ideal assault rifle round, I would start with the NATO standard 5.56×45 case, but lengthen it & neck it out. Don’t forget the 5.56×45 is a 2mm shortened .222 magnum case. Instead of shortening it 2mm, I would lengthen it 2mm, so 49 mm long. Then fit a .257/6.25mm, 120 grain lowish drag bullet. It would need a 7.62 length magazine well. This would have far more rounds in a magazine as opposed to fat 7.62 & have far gentler recoil, yet reach out more credibly than 5.56×45.
    However, the Americans have done the opposite with the .224 Valkyrie. They took the slightly fatter 6.8 SPC case & necked it down to 5.56, but gave it a very low drag 90 grain bullet. It fits in a 5.56×45 magazine well, though fewer rounds due to the fatter case. It is flatter shooting to 800 yards than the 6.5 Creedmoor, equals it at a 1000, but the Creedmoor is better beyond that.
    If for political/face saving reasons, the great & good insist on staying with 5.56 calibre, then a change to .224 Valkyrie, would provide a 5.56 that can credibly reach out to 800m.

  60. I agree that lengthening the cartridge would be a viable way to go, though I have to question trying to hit anything at 800m. To get that kind of range from an intermediate cartridge, you would have to be aiming at the sky, which would put paid to any idea of trying to hit a point target. Hell, at 300m, to hit someone in the head with an SS109/M855, you need to aim ~14 inches *above!* his head (I eyeball it as aiming at somewhere around standing hip level to hit a Fig 15 at 300m), I hesitate to even guess the amount of droppage at 800.

    You’ll need a massive change of ballistic characteristics to fire directly at a target at 800m and if I recall correctly, the muzzle velocity of an M-16 is 990m/s, which is close to Mach 3 and I don’t think you can squeeze much more flight performance out of the 5.56.

    As for lethality, the SS109 is lethal out to 1.2km, it was never about the flight range but everything to do with how the hell are you going to target and estimate droppage at such ranges to bring your round onto the target. In the past, they used ‘indirect area fire’ but these days, no one teaches indirect fire with anything less than a GPMG any more, it was deemed a waste of ammo. I don’t remember seeing many flip up quadrant sights on LMGs at all.

    We have hit a point where the round outperforms our ability to use it properly, making it ‘better’ will not improve usability since it isn’t the round that is the limiting factor but our ability to guide the round to the target.

  61. If & its a big if, there is a cartridge change, it will be driven by the fear that free world troops armed with 5.56×45, are being outranged/outgunned by enemies armed with “axis of evil” 7.62x54R.
    So any new cartridge, will at least have to match & preferably surpass the 7.62x54R.
    You could just issue more 7.62×51 rifles, but then you are back to issues with recoil, extra training/range time, plus the extra weight/size of the bigger rounds.
    The new round (if it happens), needs to equal the range of the 7.62x54R, have more “stopping power” than the 5.56×45, but not have the recoil/weight issues of the 7.62×51.

  62. Just FYI JH, the axis of evil went 5.45 decades ago. And frankly, trying to compare an intermediate cartridge with what is essentially a GPMG round is seriously not logical. Compare ARs to ARs, not ARs to MGs.

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