Minigun

Overview:

The Minigun is a 7.62 mm, multi-barrel machine gun with a high rate of fire (over 3,000 rounds per minute), employing Gatling-style rotating barrels with an external power source. In popular culture, the term "minigun" has 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 single 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. The basic weapon is a 6-barrel, air-cooled, and electrically driven machine gun. The electric drive rotates the weapon within its housing, with a rotating firing pin assembly and rotary chamber. The minigun's multibarrel design helps prevent overheating, but also serves other functions. Multiple barrels allow for a greater capacity for a high firing rate, since the serial process of firing/extraction/loading is taking place in all barrels simultaneously. Thus, as one barrel fires, two others are in different stages of shell extraction and another three are being loaded. The minigun is composed of multiple closed-bolt rifle barrels arranged in a circular housing. The barrels are rotated by an external power source: usually electric, pneumatic, or hydraulic. Other rotating-barrel cannons are powered by the gas pressure or recoil energy of fired cartridges. A gas-operated variant, designated the XM133, was also developed, but was not put into production. While the weapon can feed from linked ammunition, it requires a delinking feeder to strip the links as the rounds are introduced to the chambers. The original unit was designated MAU-56/A, but has since been replaced by an improved MAU-201/A unit. G.E.'s minigun is in use in all major branches of the US military, under a number of designations. The basic fixed armament version was given the designation M134 by the U.S. Army, while the exact same weapon was designated GAU-2/A by the U.S. Air Force. The USAF weapon has three subvariants, while the US Army weapon appears to have incorporated any new improvements without a change in designation. Available sources show a relation between both M134 and GAU-2/A and M134 and GAU-2B/A. A separate variant, designated XM196, with an added ejection sprocket was developed specifically for the XM53 Armament Subsystem on the AH-56 Cheyenne helicopter. Another variant was developed by the U.S. Air Force specifically for flexible installations, at the time primarily for the UH-1N helicopter, as the GAU-17/A. The primary end users of the GAU-17/A have been the U.S. Navy and the U.S. Marine Corps, who mount them as defensive armament on a number of helicopters and surface ships. The weapon is part of both the A/A49E-11 armament system on the UH-1N and A/A49E-13 armament subsystem on the HH-60H aircraft. The weapons on these systems feature a selectable fire rate of either 2,000 or 4,000 rpm. There is mention of a possible GAUSE-17 designation (GAU-Shipboard Equipment-17), in reference to the system when mounted on surface ships, though this would not follow the official ASETDS designation system's format.

Specifications:

Type

• Gatling-type machine gun.

Place of Origin

• United States.

Cartridge

• 7.62x51mm NATO.

Caliber

• 7.62 mm (0.308 in).

Action

• Electrically driven rotary breech.

Rate of Fire

• 4,000 RPM (practical maximum)/ 6,000 RPM in some applications.

Feed System

• Disintegrating cartridge belt or linkless feed (dependent on installation).

Sights

• No fixed sights.