Post the 1998 SDR, when the UK was caught in the grip of the go fast, go hard, go home RMA craze a couple of C130 deployable artillery weapons got very close to coming into service.
Lightweight Mobile Artillery Weapon System – Rocket (LIMAWS-R)used the same MLRS launching system as found on the the US HIMARS truck mounted system, basically, an MLRS system cut in half, 6 MLRS/GMLRS rockets or one ATACMS rocket.
The UK version swapped out the US FMTV truck for a Supacat designed chassis, the same underlying HMT 600 high mobility chassis as now used on the Coyote.
The Lightweight Mobile Artillery Weapon System – Rocket used the larger SPV 800 chassis and the BAE M777 155mm howitzer.
Iraq and Afghanistan put paid to LIMAWS, Rocket and Gun, but both were interesting concepts.
C130 portability is now somewhat like tits on a fish, in the medium term, the UK will only have the C17 and A400.