FN MAG

The FN MAG (French: Mitrailleuse d'Appui Général, English: General Purpose Machine Gun, lit. 'Machine gun for general support') is a Belgian 7.62 mm general-purpose machine gun, designed in the early 1950s at Fabrique Nationale (FN) by Ernest Vervier. It has been used by more than 80 countries and it has been made under licence in several countries, including Argentina, Canada, Egypt, India, and the United Kingdom.

The MAG is available in three primary versions: the standard, infantry Model 60-20 machine gun, the Model 60-40 coaxial machine gun for armoured fighting vehicles, and the Model 60-30 aircraft variant.

After World War II the Swedish Army, who used two 6.5×55mm versions of the Browning Automatic Rifle (BAR) since the 1920s, wanted to replace them with a belt-fed version. FFV-Carl Gustaf tried to design a derivative, but their belt feeding mechanism (placed below the action, like on the BAR) did not pass military trials. Therefore FN Herstal was approached, and Belgian designers came up with the idea to flip the BAR action upside down and mate it with the proven MG 42 belt-feeding mechanism. The work was started in the late 1940s by Dieudonné Saive and finished by Ernest Vervier in 1953, with Swedish trials beginning in 1955.

The MAG served as a complement to the FN FAL battle rifle. It first entered production in 1958 (Ksp 58 chambered in 6.5×55mm), and it is sometimes referred to as the MAG-58.

The MAG Model 60-20 is an automatic, air-cooled, gas-operated machine gun, firing belt-fed 7.62×51mm NATO from an open bolt. The MAG uses a series of proven design concepts from other successful firearms, for example the locking mechanism is modeled on that of the Browning M1918 (BAR) automatic rifle, which FN produced under license with some adaptions, and the feed and trigger mechanisms are from the WW II-era MG 42 universal machine gun.

The MAG operates via a long-stroke piston system, which utilizes the ignited powder gases generated by firing vented through a port in the barrel to propel a gas piston rod connected to the locking assembly. The barrel breech is locked with a vertically tilting, downward locking lever mechanism that is connected to the bolt carrier through an articulated joint.

The locking shoulder and camming surfaces that guide the locking lever are located at the base of the receiver. The unlocking sequence starts after 15 mm (0.6 in) rearward gas piston rod movement to keep the breech block fully locked until the bullet has left the gun barrel and the high-pressure propellant gas pressure has dropped to a safe level.

The MAG fires from an open bolt. Both the spring-powered extractor and ejector are contained in the bolt. After firing, spent cartridge casings are removed downwards through an ejection port normally covered by a spring-loaded dust cover at the bottom of the receiver. The machine gun has a striker firing mechanism (the bolt carrier acts as the striker as it contains a channel that houses the firing pin, which protrudes out from the surface of the bolt upon firing), an automatic-only trigger assembly and a manual cross-bolt push-button safety, which is located above the pistol grip.