GAU-8 Avenger
The GAU-8/A Avenger is a 30 mm, seven-barrel Gatling gun that is mounted on the United States Air Force's A-10 Thunderbolt II. It is the largest (it is the size and weight of a family saloon car), heaviest and most powerful aircraft gun in the United States military. Specifically designed to be a "tank buster", the gun can deliver a rate of fire of an astonishing 4,000 shots per minute although, in use, it is limited to two-second bursts before it overheats.
Developed as part of the A-10 program by Fairchild Republic, both the aircraft and the gun entered service in 1977 (it is often said that the A-10 was designed around the gun, which fills half of the aircraft's fuselage). The gun is no longer in production. It was produced by General Electric, though General Dynamics Armament Systems is now responsible for support.
In the tank-busting role the gun fires rounds with depleted uranium penetrators. Just six rounds will destroy a modern Russian tank and the effect on lighter vehicles such as APCs is devestating. The use of depleted uranium is controversial with some believing it has led to ill health in servicemen who have handled the rounds and also people who survive attacks, although extensive scientific studies by the UN have found no evidence to support this. The gun can also fire a mix of ammunition utilizing four High Explosive Incendiary (HEI) rounds followed by a Armor Piercing Incendiary (API) round.
The gun is also used on naval ships in the Goalkeeper CIWS.
It is interesting to note that, assuming unlimited ammunition and a constant rate of fire, the Avenger's recoil is sufficent to counteract the forward thurst of an A-10.