The M134 Minigun
The M134 Minigun is a 7.62 mm, six-barreled machine gun with a high rate of fire (2,000 to 6,000 rounds per minute), employing Gatling-style rotating barrels with an external power source. The term "Minigun" has popularly come to refer to any externally-powered Gatling gun of rifle caliber, though the term is sometimes used to refer to guns of similar rates of fire and configuration, regardless of power source and caliber. Specifically, minigun refers to a specific model of weapon, originally produced by General Electric. The "Mini" of the name is in comparison to designs that use a similar firing mechanism but larger shells, such as General Electric's earlier 20 mm M61 Vulcan, and "gun" referencing the delineation between a cannon, that of a caliber higher than 20 millimeters--and gun--within certain ranges.