Minigun

The M134 (or GAU-2/a) Minigun is a gatling-style machine gun commonly used as a door gun on helicopters. Firing at up to 6000 RPM it is an ideal suppression weapon. The name is derived from the M61 Vulcan, a 20mm gatling gun used on jet fighters, with the minigun being a "miniaturized" version as it fires a rifle cartridge, 7.62x51mm NATO, instead of an autocannon round.

Call of Duty 4
In Call of Duty 4, the Minigun is used by Soap in Heat to provide supporting fire for his retreating SAS allies. The Minigun is attached to a downed helicopter (the same helicopter can be seen in the same position in Safehouse, but the minigun is not present) just past the church.

The Minigun can really do a lot of damage because of its high firing rate, but it needs to be spooled up and can overheat. However, keeping it spooled will not overheat the gun. It's also worth noting that the minigun is highly effective against the helicopters in the mission "Heat", it can normally down one in a small burst and will stop the troops getting off and engaging the player later on in the mission. On Arcade Mode a helicopter kill is worth 1000 points. A quick spray around will down them all very quickly.

The minigun is easily the most damaging weapon in the game, instantly destroying anything from helicopters to cars to enemy soldiers.

Call of Duty 4: Modern Warfare (DS)
The Minigun is constantly used throughout the Helicopter levels in the game, where you usually need it to eliminate opposition or take out objectives. Unlike its console counterparts it cannot overheat and does not need to be spooled up before firing, making it an extremely effective weapon.

Call of Duty: Modern Warfare 2
The Minigun returns in MW2. It is featured far more often than in Call of Duty 4 and also now has a much shorter and more realistic spooling time. It can be seen in the single player mission Team Player mounted on a Humvee. It is also seen on various helicopters, notably in the single player mission Of Their Own Accord. This same setup is used in the Spec Ops mission Big Brother. The new Sentry Gun, available in the campaign, special ops and multiplayer, also uses the M134. Additionally, in the mission The Enemy Of My Enemy, it is seen mounted to black SUVs used by Shadow Company. The HMMWV-mounted minigun is far more inaccurate than the other implementations, firing in a wide, but consistent circular spread. the helicopter mounted miniguns fire with a much tighter spread. In real life, the minigun is very accurate, and does not have the circular spread shown in the HMMWV version. In Multiplayer, the Minigun appears in select levels, replacing the M249 as the standard stationary gun. This was most likely a balance issue, due to players in MW1 constantly going prone, shooting off a burst, then going prone again automatically due to the way the game handles it. Now, players have to expose themselves for the short spool time before being able to shoot.

Holding the left trigger zooms in and spools the gun barrels without firing, eliminating the "warm up" time.



Trivia

 * In the game, the minigun is actually placed in the wrong opening. It should be placed in the "window" just behind the cockpit, just like the one you see on the friendly helicopter in Crew Expendable. However, due to the lack of the minigun in the mission prior, it could be assumed the SAS found it and moved it to a more useful position as they did with the Javelin missile in the church tower.
 * In Modern Warfare 2, minigun does not overheat in Campaign or Multiplayer.
 * In the mission "Heat", Soap is ordered to lay down suppressive fire on the approaching enemies using the minigun. This is not possible as the minigun requires electricity, which in turn is generated by the chopper. The wreckage suggests that the minigun is useless. However if the minigun had been found, it may use a jury-rigged power source like a car battery.
 * Also in Heat if you stay on the minigun after Captain Price tells you to fall back to the tavern Captain Price will repeat "Soap, get off the minigun," or phrases like that until you get off of the minigun.
 * In multiplayer mode, if you use a mounted minigun while wielding any sniper rifle, you can hold your breath while ADS with the minigun. It does not affect your accuracy, however.
 * The Sentry Gun is a minigun.
 * In multiplayer if a player uses a minigun, they will not see your fingers on the trigger.
 * If a player is using a class set up with one man army, their is a glitch where a player can use one man army to switch to a class with riot shield and during the switch can use the Minigun, but once complete the person will have a riot shield in front of them as they use the minigun.thumb|right|300px|Minigun with Riot Sheild