What Caliber Is a Minigun?

What Caliber Is a Minigun?

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A six-barreled rotary machine gun that’s vehicle or sea or aircraft-mounted is used to provide a high rate of light armament is termed a lethal weapon. Its Gatling style concept has seen lengthy service life since the Vietnam War and other global conflicts. But what caliber is a Minigun?

The M134 Minigun’s caliber is 7.62mm and is chambered in 7.62×51mm NATO, the standard military version of the .308. It is belt-fed, firing at a 2,000 to 6,000 round per minute rate of ammunition exhale, and powered by an electric motor. This weapon has six Gatling-style rotating barrels and has been manufactured by General Electric and Dillon Aero, amongst other arms manufacturers.

Despite being deployed since the 1960s, the M134 or its improved variants continues in service today. The Minigun arose from an existing 20mm M61 aircraft gun called the Vulcan, redesigned by GE to become much more compact. In this article, you’ll find out the caliber for this belt-fed special purpose weapon, so keep reading.

Brief History on the Development of the General Electric Minigun

The Minigun is derived from a hand-cranked mechanical weapon invented by Richard Jordan Gatling in the 1860s. He later replaced the manual action with an electric motor for the firearm that bore the Gatling gun’s name. Even after slowing down the mechanism, this firearm has a 3,000 round-per-minute rate of fire, three times that of any modern single-barreled machine gun.

In 1960, the General Electric corporation’s weapons branch started developing an externally powered, rifle-caliber Gatling machine gun. That was after they’d fielded their 20mm M61 Vulcan automatic gun used in aircraft and air to air applications. In 1962 and 1964, the prototypes of this weapon were fired, named the Minigun for being a predecessor of the larger Vulcan.

It was mounted on an AC-47 gunship for combat trials, and mass production commenced after these successes. The US Army adopted the Gatling type machine gun as the M134, while the Air Force and the Navy dubbed it GAU-2B/A and GAU-17/A, respectively. More than 10,000 Miniguns were produced and delivered to the military by 1971.

Many were used in airborne applications, installed in the forward or side-firing mountings on helicopters and fixed-wing aircraft. These include the UH-1 Huey, AH-1 Cobra, and the HH-53 Green Giant. They provided excellent sustained suppressive fire and denial of area capabilities due to their high firing rate. Infantry applications have, however, been limited due to the Minigun’s external power requirements and overall weight of the system.

What Description Is Given of the Minigun and Its Caliber Chambering?

In modern times, a US-based armament manufacturer, Dillon Aero, resumed production of the Minigun. Improvements included streamlining and refurbishing the overall design that resulted in the M134D. Titanium housing resulted in weight-saving, designated the M134D-T and a hybrid became the M134D-H. Another arms producer, Garwood Industries, also moved in on these modifications, adding inherent optics support, which spawned the M134G.

Ammo for the Minigun originates from an ammunition box belt-fed, the firing action stripping it from its linking. Each 7.62x51mm NATO round is fired through an available barrel, ejecting the casing and the belt link components. Once the cycle is completed, the next barrel is lined up to repeat the process, producing impressively high volumes of fire.

Accidental discharge of cartridges due to heat, also called cook-off, is prevented by design. When the trigger is depressed, feed the bolt, and barrel assembly automatically shuts off. That keeps fresh ammo from coming into play while the barrels are spinning before they come to rest. An electrically driven rotary breech system offers a muzzle velocity of over 2,800 feet per second for a maximum range of 3,680 yards.

M134 Miniguns have an overall length of 31.5 inches, with a 21.85-inch barrel length. The weapon weighs 35 pounds when empty and more with the mount and batteries included. That makes the firearm rare in infantry applications or outside of vehicular mounting. Besides, this machine gun has extremely high recoil, generating at least 150 pounds on average and 300 pounds peak.

What Improvements Have Been Made to the M134 Minigun?

The M134D from Dillon Aero has proven to be the most reliable Minigun so far, a weapon offering loading simplicity, ease of operation, maintenance, and extensive capacity. It’s designed for accuracy and speed but comes off as virtually recoil-free. You can achieve extreme shot density, suppressing multiple targets in a compressed period of rapid shooting.

Chambered in 7.62x51mm NATO, the M134D has magazines of up to 4,000 rounds and has a fixed firing rate of 50 rounds per second or 3,000 rounds per minute. This Minigun has let off four rounds from the time it takes to fire a single round from an M240 machine gun. That much shooting activity requires a lot of juice to achieve this rate. The electrical motor drive uses up between 24- and 28-Volts Direct Current at 58 amperes.

Other improvements done by Dillon Aero include the ammunition belt de-linker that I mentioned earlier. The barrel, bolt, and housing also got worked on, and between 1997 and 2001, at least 25 to 30 Miniguns were rolling out of their Arizona plant. By the time the 9/11 attacks happened that year, they were working on a new bolt design to increase service life and performance.

To improve on weight reductions, Dillon also added a titanium rotor and housing, designating this Minigun the M134D-T. They effectively reduced weight from 61lbs. to 41 pounds while giving the housing a 500,000-round lifespan before replacing it.


7.62×51mm NATO or .308 answers the question, what caliber is the Minigun? It’s a specialized mounted weapon, belt-fed, and utilizes a Gatling-style six-barrel operation from an external electric source. The M134D, currently in service with various arms of the US military, is a much-feared machine gun that quickly suppresses attacks and engages multiple targets seamlessly.

Its barrel clusters rotate anticlockwise when viewed from its breech end. While the original M134 was designed with a fixed rate of 6,000 rpm, it was unsustainable, necessitating redesign.  Motor transmission housing gave the weapon a 2,000 to 4,000 round per minute variable speed.

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