The M134 Minigun is an American 7.62×51mm NATO six-barrel rotary machine gun with a high rate of fire. It features a Gatling-style rotating barrel assembly with an external power source, normally an electric motor. The "Mini" in the name is in comparison to larger-caliber designs that use a rotary barrel design, such as General Electric's earlier 20 mm M61 Vulcan, and "gun" for the use of rifle ammunition as opposed to autocannon shells.
View of M134 from inside a UH-1 Huey, Nha Trang AB, 1967
A U.S. Air Force rotary-wing crewman fires a minigun during the Vietnam War.
A Royal Navy minigun, separated from mounting and ammunition
A U.S. Navy Special Warfare Combatant-craft Crewman (SWCC) on a SOC-R firing a Minigun at the Stennis Space Center in Mississippi, August 2009
The 7.62×51mm NATO is a rimless, straight walled, bottlenecked rifle cartridge. It is a standard for small arms among NATO countries.
Unfired 7.62×51mm NATO round (B) next to three recovered bullets, showing rifling marks (A)
.50 BMG, .300 Winchester Magnum, 7.62 NATO, 7.62×39mm, 5.56 NATO, and .22 LR
Service rifle cartridges loaded with projectiles: (left to right) 7.62×54mmR, 7.62×51mm NATO, 7.62×39mm, 5.56×45mm NATO, 5.45×39mm
7.62×51mm NATO cartridge case ejection from a British L129A1 Sharpshooter Rifle after firing L59A1 "High Performance" ammunition featuring a 10 g (155 gr) bullet
