The L21A1 RARDEN ("Royal Armament, Research and Development Establishment" and "Enfield") is a British 30 mm autocannon used as a combat vehicle weapon.

The Rarden gun does not require an external power source and can remain in action even if the vehicle is disabled, provided that provision is made for manual traverse and elevation of the turret or mount and for sighting the weapon.

British Aerospace (BAe) bought Royal Ordnance on 2 April 1987 and the closure of RSAF Enfield was announced on 12 August 1987.

There were problems with the long-barrelled weapon fouling external fittings (which meant that the turret had to be mounted on a three-inch spacer) and with blast damage to the flotation screen.

[3] In March 2008, the UK Ministry of Defence announced that a 40CT cannon[4] firing Cased Telescoped Ammunition developed by the Anglo-French firm CTA International had been selected to replace Rarden in the Warrior IFV and to be fitted to the reconnaissance vehicle which would replace the existing range of CVR(T) vehicles.