The Royal Ordnance L30 rifled tank gun has been manufactured at Nottingham for installation in the Challenger 2 MBT currently being built by Vickers Defence Systems at Newcastle-upon-Tyne for Oman and the UK.

At one time it was expected that the L30 gun was to be backfitted into the current Challenger 1 MBT as a replacement for the exisiting L11, but this is no longer being carried out. With the introduction of the Challenger 2 the older Challenger 1 MBT's will be phased out of service with the British Army.

Early in 1999, it was stated that Jordan would soon take delivery of a batch of Challenger 1 MBTs to replace its current Tariq (upgraded Centurion MBTs).

The L30 rifled tank gun is fitted with a new breech mechanism known as the 'split sliding-block breech' in which the obturation ring (Crossley pad(obturation), made necessary by the Combustible Case Charges, (CCC) is employed in a split rising block. This rising block is held in place for firing and a second rising block falls to release the upper one after firing. The two blocks can then fall together for the reloading process. This system combines strength with compactness, and the whole operation sequence can be made semi- or fully automatic.

The gun barrel is a monobloc-construction, swage-autofrettaged Electro-Slag Refined (ESR) steel tube with 1:18 right-hand twist rifling and is chrome-plated in the bore and chamber The barrel life of the L30 is expected to be of the order of 500 EFC, as RDX in stick form is the propellant used. An integral section near the | muzzle accommodates a muzzle reference sight.

The L30 will fire all current 120 mm projectiles of the current L11 gun with the exception of the APDS. The CHARM 1 and CHARM 3 projectiles have a DU penetrator for enhanced armour penetration characteristics.

In production. Installed in the Challenger 2 MBT. In service with Oman and the United Kingdom. The L30 is also installed in the Vickers Defence Systems Challenger 2E which has been developed for the export market.