A 120 mm calibre recoilless anti-tank rifle, the L6 Wombat (Weapon of Magnesium, Battalion, Anti-Tank) was a lightened version of the previous L2 BAT (Battalion, Anti-Tank). It was used by air mobile (infantry battalions) plus mobile troops such as the Parachute Regiment and Royal Marine Commandos. It entered service in 1964, rapidly replacing earlier versions in service with the regular army. However, it never fully replaced MOBAT and CONBAT with infantry units of the Territorial Army.
Wombat was used until anti-tank guided missiles such as Vigilant and MILAN took their place. However, they remained in anti-tank platoons in Berlin to supplement MILAN until the late 1980s due to the expected engagement ranges (the wire-guided MILAN being potentially difficult to use in built-up areas). Wombat would have been used in ‘shoot-and-scoot’ attacks mounted on the back of stripped-down Land Rover vehicles.
The L6 Wombat comprised the L12A3 BAT gun mounted on a new, light-weight carriage with a light-weight, horizontally-hinged breech. The gun was mounted on a small two-wheeled carriage which was removable in order to be moved over obstacles, and then locked onto the carriage again. Wombat required a 3-man crew. The weapon had to be carried in the rear of a specially-adapted Land Rover. It could also be mounted on the FV432/40 armoured personnel carrier. It was NOT a towed weapon, as is commonly misconceived. During the Cold War era, NATO and the British Royal Marines also used the Swedish-made Aktiv ST4 Snow-Trac (SMM3543) 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. However, they were never off-loaded from the transport ships.
The usual round for Wombat was HESH which it could fire to around 1,800 metres. When fitted with an M8C .50 calibre spotting rifle (which fired a tracer round), it could engage targets out to 2,000 m. The strike would be observed by the No.1 who called the fall of shot. The No.2 maintained the spotting rifle and observed the back blast area. The HESH round could defeat 400 mm (16 inches) of armour. Other ammunition types included the canister and modified canister rounds. The latter released flechettes, or small darts, giving a shot-gun 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 the large venturi. While the L6 Wombat was a powerful weapon, it created such a significant back blast signature when fired, that it was difficult to keep its location hidden after the first round.