The term 'autocannon' is sometimes used to refer to fully automatic weapons with a caliber of 20 millimeters or larger. The largest caliber still considered an autocannon is somewhat arbitrary, though it is generally agreed that a cyclic rate of 1 round/sec or greater is required. Such weapons are often used for attacking lightly armored vehicles, defending against aircraft, boats and small ships.
Examples are too numerous to list exhaustively, but a number of well-known autocannons exist.
- General Electric M61A1 Vulcan 20mm Gatling (USA, others)
- Bushmaster Mk. 38 25mm belt-fed (USA, others)
- Bofors Mk. 110 57mm naval gun (4 rds/sec. Sweden, Canada, others)
- OTO Melara 76mm Super Rapide (2 rds/sec. Italy, USA, others)
- Kalashnikov AK-630 30mm Gatling (Russia, others)
- Grzayev-Shipunov GSh-1-30 30mm aircraft cannnon (Russia, others)
- GAU-12 Equalizer 25mm 5-barrel Gatling (USA, Britain, others)
- DEFA 30mm aircraft cannon (France, others)
- Mauser BK27 27mm revolver cannon (Germany, Poland, Italy, others)
- Kalashnikov AK-276 twin 76mm (3 rds/sec. Russia, India)
- GAU-8 Avenger 30mm 7-barrel Gatling (Aircraft and naval versions. USA, Britain, Netherlands, others)
- OTO Breda Twin Fast 40 (DARDO) 40mm twin (10 rds/sec. Italy, Argentina, Chile)