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.

[8] 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.

[9] The work was started in the late 1940s by Dieudonné Saive and finished by Ernest Vervier in 1953, with Swedish trials beginning in 1955.

[12] 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.

Guide rails that support the bolt assembly and piston extension during their reciprocating movement are riveted to the side plates.

[13] The MAG is also equipped with a fixed wooden stock (later production models feature polymer furniture), pistol grip, and carrying handle.

In the infantry assault role, the weapon can be fitted with a sheet metal container that houses a 50-round belt and is attached to the left side of the receiver.

The top of later production model receivers often feature a MIL-STD-1913 rail as a mounting platform for firearm accessories like (low light) optical sights and night-vision devices.

For carrying or use as a forearm, the aluminum legs can be folded back and secured in slots under the receiver by hooks and a spring-loaded catch.

[13] In the static medium machine gun sustained fire support role, the weapon is mounted on a tripod that offers a higher degree of accuracy and control than the bipod, for example the FN 360° tripod, which features an elevation adjustment mechanism that enables the weapon's bore axis to be maintained from 300 mm (11.8 in) to 600 mm (23.6 in), has a 30° to +15° elevation change and a 360° traverse range.

Variants of the FN MAG were manufactured by at least ten companies: FN Herstal, Fabricaciones Militares, Changfeng Machinery, Indian Ordnance Factories, Carl Gustaf Stads Gevärfaktori, the Ordnance Development and Engineering Company of Singapore, Canadian Arsenals Limited, the Royal Small Arms Factory, Heckler and Koch, U.S.

[18][19][20][21][22] The vehicle-mounted variant of the MAG lacks a stock, bipod, carry handle, pistol grip, ejection port dust cover and a mount for optical sights.

The official British Army designation for the current version is the L7A2 GPMG (General Purpose Machine Gun).

The LSW was intended to replace both the L7 and the L4 in the light machine gun role, but dissatisfaction with the L86's sustained fire capabilities and reliability resulted in combat units continuing to utilize the L7 whenever possible (although neither it, nor its 7.62×51mm NATO ammunition was supposed to be issued to infantry platoons).

However a review of requirements led to the withdrawal of both the L110A2 LMG and L86A2 LSW from service in 2018, with the 7.62 mm L7A2 resuming its place in the British Army infantry section.

In 1961, the Royal Small Arms Factory, Enfield (now BAE Systems) in the United Kingdom, undertook licence production of the MAG in the following versions: L7A2, L8A2, L37A2, L20A1 and the L43A1.

[25] With the tripod and FGM-148 Javelin sight unit indirect fire configuration, British troops in Afghanistan used the L7A2 at ranges of and over 2,700 m (2,953 yd).

[26] The average 1,884 m (6,181 ft)[27] elevation of Afghanistan and accompanying low ISA air density[28] significantly contribute to extending the useful maximum range of small-arms projectiles.

The machine gun can be used in the ground role for self-defense, by dismounted vehicle crew members, the egress kit consists of an L7A2 barrel, bipod and buttstock.

The C6 GPMG is also mounted on a variety of vehicles, including the G-Wagon LUVW, LAV III, Coyote, Leopard C2, and CH-146 Griffon helicopter.

In September 2018, Canada began fielding an improved C6A1 FLEX version; changes include a polymer buttstock which is more durable and easier to decontaminate in a CBRN scenario than the original wooden stock, M1913 picatinny rails for the attachment of pointing devices and optical sighting systems, and an adjustable gas tube regulator to control the rate of fire.

[37] The XY, 7.62 × 51 is a true copy of the FN MAG made with a wooden stock by Yunnan Xiyi Industry Company Limited.

[19][21] The German arms manufacturer, Heckler & Koch, whose 1999 to 2002 owner BAE Systems — as the result of a 1999 merger between British Aerospace and Marconi Electronic Systems, Heckler & Koch was owned by the resulting BAE Systems — had executed a midlife improvement program of the L7A1 (FN MAG 60.20 T3) to the upgraded L7A2 (FN MAG 60.20 T6) version under contract for the British Ministry of Defence, attempted to make their own variant of the FN MAG.

This version is equipped with an iron sight line that consist of a rotary rear drum and hooded front post and Picatinny rail atop the receiver.

[41] In 2020, Iranian nuclear scientist Mohsen Fakhrizadeh was killed by Mossad with an FN MAG, redesigned to fire from a remote control.

Kulspruta 58 B: In the early 1970s, the weapon was modified with a new gas regulator and at the same time the barrels were replaced to the new standard 7.62×51mm NATO, same as used by the Ak 4.

Some of the modifications:[45] On January 14, 1977, the US Army awarded a contract to FN Herstal for the delivery of a modernized Model 60-40 variant tank machine gun designated the M240.