The GAU-8 Avenger is a Gatling type autocannon. It has 7 barrels and is mounted inside the American A-10 attack aircraft, as well as forming the basis of the Dutch Goalkeeper CIWS. Originally, it was capable of firing 4,200 rounds per minute in the high setting or 2,100 rpm in the low setting. This has since been changed to a fixed rate of 3,900 rpm. It is chambered for the 30x173mm cartridge. It has a muzzle velocity of 1,070 meters per second—well over Mach 3. It is designed specifically for the antitank role. It is capable of penetrating 69mm of armor at 500 meters, and 38mm of armor at 1,000 meters. Its recoil force is 10,000 pounds force (45 kN).When mounted upon the A10 it Is mounted slightly off centre so that the recoil from such a powerful system doesn't affect the plane while it's firing. The spent shells eject back into the ammunition drum, partly as a safety measure because of the risk of the large shells going into the engine intakes, when mounted on the A-10.
- Some of its technology has been transferred to the 25mm GAU-12/U Equalizer.
- The GAU-13/A is a 4 barreled derivation of the GAU-8.
The GAU-8 was created as a parallel program with the A-X (or Attack Experimental) competition that produced the A-10. The specification for the cannon was laid out in 1970, with General Electric and Philco-Ford offering competing designs. Both of the A-X prototypes, the YA-10 and the Northrop YA-9, were designed to incorporate the weapon, although it was not available during the initial competition; the M61 Vulcan was used as a temporary replacement. Once completed, the entire GAU-8 assembly (correctly referred to as the A/A 49E-6 Gun System) represents about 16% of the A-10 aircraft's unladen weight. Because the gun plays a significant role in maintaining the A-10's balance and center of gravity, a jack must be installed beneath the tail of the plane whenever the gun is removed for inspection in order to prevent the aircraft from tipping rearwards.
- Precision: 80% of rounds fired at 4,000 feet (1,200 m) range hit within a 40 feet (12 m) diameter circle
- PGU-14/B API Armor Piercing Incendiary (DU)
- PGU-13/B HEI High explosive incendiary
- PGU-15/B TP Target Practice
- Armor penetration:
BHN-300 RHA, attack angle 30 degree
- 76mm at 300 meters
- 69mm at 600 meters
- 64mm at 800 meters
- 59mm at 1,000 meters
- 55mm at 1,220 meters