The L2 BAT was a 120 mm calibre recoilless anti-tank rifle used by the British Army. It was also produced in the MOBAT version without a gun shield, and the ConBAT version with a new spotting rifle attachment. The L6 Wombat version was greatly lightened through the use of magnesium alloys. The Wombat was used by mobile units such as paratroopers and marines. BAT was developed from the wartime Ordnance, RCL, 3.45 in, replacing it and the Ordnance QF 17-pounder to become the standard anti-tank weapon of the Army in the post-World War II era. The BAT and MOBAT were used until anti-tank guided missiles, such as Vigilant and MILAN, took their place. WOMBAT remained in anti-tank platoons in Berlin to supplement MILAN until the late 1980s, due to the expected engagement ranges should the Warsaw Pact have ever attacked. The wire guidance of MILAN would also have been problematic in the built up areas of Berlin. It was envisioned that Wombat would be used in 'shoot and scoot' attacks mounted on the back of stripped down Land Rover vehicles. The Wombat was a development version which replaced the earlier BAT and MOBAT weapons. It was in turn replaced by anti-tank guided missiles. The L6 Wombat itself comprised the L12A3 BAT gun, but mounted on a new lightweight carriage. The vertically sliding breech of the BAT and MoBAT was replaced by a lighter horizontally hinged breech. The Wombat was mounted on a small two wheeled carriage, which was removable in order to be moved over obstacles and then locked to the carriage again. The weapon was normally carried in the rear of a specially adapted Land Rover. The Wombat could also be mounted on the FV432/40armoured personnel carrier. The usual round for Wombat was a HESH, which it could fire out to around 1,800 m. The HESH round could defeat of armour. Other ammunition types include the canister and modified canister rounds. The latter released flechettes, or small darts, giving a "shotgun" effect. These rounds could be used against infantry in the open. The base of the BAT cartridge case was frangible, the reaction gases venting directly backwards through a single large venturi. This was in contrast to the US recoilless designs, which used a frangible sidewall to the cartridge case and multiple venturi. During the Cold War era, NATO and British Royal Marine forces used the Swedish made Snow Trac as a carrier for the L6 Wombat in the snow-covered mountains of Norway. Wombats were among the anti-tank weapons taken by the Parachute Regiment to the Falklands War in 1982, but they were not off-loaded from the transport ships.