The Grand Theft Auto: Vice City and Grand Theft Auto: San Andreas renditions are based on a man portable version of the M134 Minigun, while the Grand Theft Auto: Liberty City Stories version is based off the M197 tri-barreled Gatling. It has an incredible rate of fire and can annihilate most vehicles in almost less than a second around a certain radius. In Vice City, the minigun was perfect for mowing down targets level with the player, however, it could not be aimed manually. Instead, it shoots upwards automatically to E.G. helicopters, similar to the Rhino. In GTA San Andreas, thanks to the new aiming system, the minigun could be pointed in any direction, making shooting higher targets much easier, but also dangerous if the helicopter would crash into the ground and explode dangerously close to the player. It is almost 100% accurate as there is no recoil, but it can't lock on to a target which isn't much of a problem due to the very high power of each individual round and the amount of ammo it carries. Once equipped with a minigun, it's possible to complete some mission objectives that usually require other weaponry, such as the gun emplacement in Up, Up and Away!. In San Andreas the gun can only be found at spawn points (or provided during missions) and cannot be purchased at Ammu-Nation. In San Andreas a mounted Minigun is used in several missions with unlimited ammunition. These missions include Air Raid, The Da Nang Thang, and Up, Up and Away!.
For Grand Theft Auto IV, the minigun was planned to be the second heavy weapon, the first one being the rocket launcher, but it was dropped in the end, due to unknown reasons. By using the remaining data in-game, it appears to carry a 750-bullet load and to be able to kill any person (armored or not) with one shot, making it the most powerful weapon in the game. Miniguns are also mounted on Annihilator and Buzzard helicopters. Both fire normal 7.62×51 millimeter cartridges, but the Annihilator fires about 1,000 rounds per minute, which is unrealistically slow, by about 5,000 rounds per minute. This is probably to prevent helicopter pilots from being able to literally shred players and vehicles. In The Lost and Damned, the helicopters' top speed is increased and the minigun ammunition is replaced by highly explosive cartridges that make mince meat out of pedestrians, cars, motorcycles, and even other helicopters and boats. On the Buzzard, which only appears on The Ballad of Gay Tony, there are 2 miniguns mounted, which do not overheat or need to reload and fire about 4-6,000 rounds per minute.
Grand Theft Auto V
The minigun is confirmed to appear in GTA V. The minigun is coloured military green and appears to be of a smaller model compared to previous games. It is similar in size to the model found in LCS and VCS.
Kincaid Bridge, San Fierro - On top of the southern arch of the bridge. It's not accessible until the desert and Las Venturas are unlocked, because a ghost wall is blocking the player to get the weapon. A jetpack, parachute or helicopter is also needed to get to the location.
Roca Escalante, Las Venturas - On the bottom-most level of an underground parking lot, in front of an elevator. Caution must be exercised when approaching the parkade as the previously empty structure will usually suddenly spawn a large number of vehicles when entered.
Rockshore East, Las Venturas - On top of some scaffolding in the building site, requires climbing and jumping skills or jetpack.
In addition, Carl uses mounted miniguns in the missions Air Raid, Da Nang Thang, and Up, Up and Away!, though only briefly in Da Nang Thang. If Carl is equipped with his own minigun he can use it in lieu of the mounted one in Up, Up and Away!
Note: the minigun uses the same weapon slot as the rocket launchers and flamethrower, and will therefore be replaced should any of those other weapons be equipped, such as during a mission.