FN MAG

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 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, and the feed and trigger mechanisms are from the WWII-era MG 42 universal machine gun.[8]

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 through an ejection port located at the base of the receiver (a spring-loaded dust cover of the MG42 type covers the ejection port). 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. With the safety placed in the safe setting, the sear mechanism is disabled. The safety can only be engaged with the weapon cocked.[9]

A schematic showing the mechanism of the FN MAG.

The weapon feeds from the left side from open-link, metal ammunition belts: either the American disintegrating M13 belt (NATO standard) or the segmented German DM1 belt, whose 50-round sections can be linked through a cartridge. In order to adapt the weapon to feed from one belt type to the other, several components of the feed mechanism need to be reconfigured since the position of the feed tray's cartridge stop and pawl angles in the top cover are different. The MAG features a pawl-type feeding mechanism that continues to move the feed link during both the rearward and forward cycles of the reciprocating bolt carrier, producing a smooth belt flow. The feeding mechanism's three pawls are actuated by a roller connected to the bolt carrier. The feed channel rail, feed link, both feed slides and the feed tray are chrome plated. The top cover body is an anodized aluminum casting. 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.[9]

The quick-change barrel has a slotted flash suppressor. The barrel's chamber and bore are chromium-lined and the barrel has four right-hand grooves with a 305 mm (1:12 in) rifling twist rate. Also attached to the barrel is the front sight base, carry handle and gas block (equipped with an exhaust-type gas regulator valve with three settings).[9] The barrel assembly weighs 3,050 g (6.72 lb) and of the 630 mm (24.80 in) long barrel a portion of 487.5 mm (19.19 in) is rifled.[10] The MAG takes zero shifts between barrel assemblies into account by making the front sight of the assemblies adjustable with the help of tools.

The machine gun is fitted with a folding bipod (attached to the end of the gas cylinder) that can be adjusted for height. 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. When firing from the hip, the bipod legs remain extended and the left leg is gripped for support. The bipod can be removed from the gas cylinder by tapping-out a roll pin in the gas cylinder head until it is flush and the bipod can be rotated enough to clear the gas cylinder's retaining lugs.[9]

The MAG is also equipped with a fixed wooden stock, pistol grip, carrying handle and iron sights that consist of a forward blade (adjustable mechanically for both windage and elevation) and a folding leaf rear sight with an aperture in the down position for firing distances from 200 to 800 m (219 to 875 yd) in 100 m (109 yd) increments and an open U-notch for ranges from 800 to 1,800 m (875 to 1,969 yd) graduated every 100 m (109 yd). The rear sight is hinged to a base with protective ears that is integral with the receiver's upper forging. The iron sight line has a 848 mm (33.4 in) sight radius.

The MAG's receiver is constructed from sheet metal stampings reinforced by steel plates and rivets. The front is reinforced to accept the barrel nut and gas cylinder which are permanently mounted. Guide rails that support the bolt assembly and piston extension during their reciprocating movement are riveted to the side plates. The bolt's guide rails are shaped downward to drive the locking lever into engagement with the locking shoulder, which is also riveted to the side plates. The rear of the receiver has been reinforced and slotted to accept the butt-stock.[9]

In the static machine gun 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. When used in the anti aircraft role, the machine gun can increase the cyclic rate of fire from 650 up to 1,000 rpm by regulating a user adjustable gas valve.

The Type 74 machine gun, a Taiwanese version of the MAG.

7.62 Ametralladora Tipo 60-20 MAG, Argentine version of the FN MAG used by the Argentine Army.

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. It does, however, have a new closed-type gas regulator. Depending on the weapon's employment, the machine gun can also be fitted with an extended charging handle linkage, standard trigger group (with a pistol grip), or a specialized trigger assembly with an electrically fired trigger.

The pintle-mounted aircraft model is fed from either the right- or left-hand side exclusively with the M13 belt. Thus configured, weapons typically lack standard iron sights and are equipped with electrically powered triggers.

Tripod mounted L7A2 GPMG with a C2A2 Support Weapons Sight mounted to the left side of the L4A1 tripod

The L7 general-purpose machine gun is used by the British Army.[16] The L7 and the related L8 are license-built derivatives of the MAG. The official British Army designation for the current version is the L7A2 GPMG (General Purpose Machine Gun).

The L7 was adopted by the British forces as a replacement for the long-serving Vickers machine gun (in the medium role) and the Bren (in the light assault role), following trials in 1957. Built under license originally by Royal Small Arms Factory, Enfield Lock and currently by Manroy Engineering,[17] it serves in the British Army, the Royal Marines and other services. There have been two main variants, the L7A1 and L7A2, developed for infantry use, with the L7A2 having superseded the earlier variant. Several other variants have been developed, notably the L8 (produced in the L8A1 and L8A2 versions), modified for mounting inside armoured vehicles (the L37 variant was developed for mounting on armoured vehicles). Although intended to replace the Bren entirely, that light machine gun (re-chambered for 7.62x51mm NATO and re-titled as the L4) continued in use in jungle terrain (especially in the Far East), where there was no requirement for the medium machine gun role, and with secondary units, until the adoption of the L86A1 Light Support Weapon (LSW). 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). The British Army and Royal Marines were issued with the L110A2 (FN Minimi Para) to replace the LSW as the light section support or fire support weapon. This uses the same NATO-standard 5.56×45mm ammunition as the L85 assault rifle. 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. Other variants continue to be used in mounted roles on many British military vehicles, naval vessels and aircraft.

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. These models all use the M13 ammunition belt.

The L7A2, general-purpose machine gun, replaced the L7A1 in service with the British Army. Compared to the MAG Model 60-20, it features, among other minor changes, a 10-position gas regulator valve, a polymer butt-stock and a bracket, used to mount optical day- and night-vision sights, mounted to the left side of the receiver. In a stationary (defensive) role, the L7A2 can be mounted on the L4A1 tripod in conjunction with a C2A2 Support Weapons Sight or the sight unit used on the FGM-148 Javelin anti-tank missile system. Fired by a two-man team who are grouped in a specialist Machine Gun Platoon the L7A2 in conjunction with a C2A2 Support Weapons Sight can provide battalion-level direct support fire at ranges up to 1,800 m (1,969 yd) and indirect map and range table predicted support/harassment fire out to 2,500 m (2,734 yd).

The L8A2 coaxial tank machine gun (replaced the L8A1) has a different gas valve switch (closed, single-position) when compared to the analogous Model 60-40, a different flash hider and a modified cocking handle. The weapon also has a trigger group that accepts electrical input and a lever in the feed tray that enables the belt to be removed without lifting the feed tray cover.

Another tank machine gun is the L37A2 (succeeded the L37A1) designed to be mounted on tank turrets, in the commander's position, on wheeled armoured vehicles and on armored personnel carriers. It differs from the L8A2 primarily in its trigger, which was adapted from the L7A2 GPMG. 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 L20A1 aircraft machine gun was based on the L8A2, from which it differs by having an electrical trigger and a slotted flash suppressor. The L20A1 can be converted to right-hand feed by changing several components in the feed mechanism.

The L43A1, also developed from the L8A2, is a coaxially mounted tank machine gun used to sight-in the vehicle's main gun by firing ballistically-matched tracer ammunition at the target to confirm the trajectory visually. The weapon's barrel, fitted with a flash hider, has a reinforced and heavier structure that increases the weapon's accuracy especially during sustained fire.'

An unlicensed version is made for export by Norinco and made by Changfeng Machinery Co., Ltd as the CQ, 7.62 × 51 (Copy Version) (Now renamed CS/LM1 as of 2006)[18] with an adjustable butt.[19][13] The weapon was officially produced in 2006[20] and it was showcased in various foreign military expo conventions.[18]

The XY, 7.62 × 51 is a true copy of the FN MAG made with a wooden stock by Yunnan Xiyi Industry Company Limited.[12][14]

German arms manufacturer, Heckler & Koch, attempted to make their own variant of the FN MAG; it was designated the HK 221. This version was meant to compete in the machine guns trials held by the German and French military between 2007-2008; the trials concluded with the French military continuing to use the original FN MAG while the German military chose the HK121.[21]

All versions are licence-manufactured by FFV-Carl Gustaf. The Swedish abbreviation for kulspruta (machine gun, lit. "bullet sprayer") is Ksp. Strv is the abbreviation of Stridsvagn (battle tank).

A left-side view of the Kulspruta 58B (Ksp 58B).

Kulspruta 58: Ksp 58, adapted in 1958 using the 6.5×55mm rifle cartridge which at that time was the standard cartridge in the Swedish Army.

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. Ksp 58 replaced the considerably heavier Ksp m/42B in the infantry units. It can be fed with non-disintegrating DM1 or disintegrating M13 linked ammunition belts.

Kulspruta 58 C: On Combat Vehicle 90, this version replaced the previously used Ksp m/39 in the third quarter of 2004.

Kulspruta 58 Strv: stripped variant mainly used for fixed mounting in tanks. Phased out along with Stridsvagn 103.

Kulspruta 58 D: Reserved designation for the renovated and modified Ksp 58B. The trial version is referred to as 'Ksp 58 DF', where the 'F' stands for 'Försök' (Experimental). Some of the modifications:[22]

• A MIL-STD 1913 Picatinny rail system added. Half of the weapons feature an adjustable rail - the others a fixed.
• Red dot sight (Aimpoint CompCS).
• The carrying handle is shortened to half its original length. This was necessary in order to fit an extended rail for sight systems.
• Cbuttstock butt stock or folding stock.
• 100 mm shorter barrel.
• Better and shorter flash hider to reduce the length of the weapon and to produce a smaller muzzle flash, which means less disruption to the user's night vision.
• Fluted barrel in order to reduce the weight and better dissipate the heat of the barrel.
• Gas regulator has only 4 settings (instead of 8). The last position is painted red and is intended for emergency use.
• Larger 100-round ammunition pouches replaced 50-round pouches.
• New ammunition cases.
• New equipment bags.
• Bi-pod is painted green.
• There is a sheet for protection / one side green other side white / summer & winter camouflage.
• The weight of the MG is the same, but the entire system is 3 kg (6.5 lbs) lighter.

The heat shield on the M240B.

A US Marine Corps tripod-mounted M240G.

M240L paired with the lighter M192 tripod reducing system weight by 5.5 pounds (2.5 kg).

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. Initially, the firearms were produced in Belgium. Currently they are manufactured in the US by FN's US wholly owned subsidiary FNMI (FN Manufacturing Inc.) located in Columbia, South Carolina, and by U.S. Ordnance in McCarran, Nevada.

The M240 is built in several versions:

• M240 standard coaxial machine gun used in US armored vehicles. It is used in the M60 series of tanks (where it replaced the M73/M219 7.62 mm machine guns) and the M1 Abrams family. It has an electrically operated trigger and a reloading lever. Compared to the MAG Model 60-40, the M240 has a different flash hider and gas valve.
• M240B is a modernized derivative of the M240G, which features a perforated hand-guard and heat shroud, a MIL-STD-1913 rail integral with the receiver top cover, which enables the use of optical day and night sights, a new synthetic stock and a new ammunition container. It was selected to be the U.S. Army's new medium machine gun on December 1, 1995, replacing the M60 machine gun - it defeated the M60E4 during trials. M240Bs are also replacing M240Gs in USMC service. The M240B weighs 12.5 kg (28 lb) and has a length of 1,245 mm (49.0 in). The rate of fire is 650–750 rounds/min.
• M240C with a right-hand feed system. It is used in the M2 and M3 Bradley series of infantry fighting vehicles as a coaxial gun to the main armament.
• M240D an upgrade of the M240E1 and is optimized for use in military helicopters in a pintle-mounted configuration. The M240D is also supplied with an egress kit for dismounted use.
• M240E1 installed since 1987 on LAV-series wheeled armored fighting vehicles, has a spade-type grip with an integral trigger and cocking mechanism.
• M240G introduced into service with the United States Marine Corps and the 75th Ranger Regiment in the mid 1990s in place of the M60E3. The M240G is used on the M122A1 tripod for stationary use, and is also used in vehicular and aircraft mounts. It weighs 10.99 kg (24.2 lb),[8] has an overall length of 1,245 mm (49.0 in) and a rate of fire of 650–950 rounds/min.
• M240H an improved version of the M240D. The M240H features a rail-equipped feed cover, an improved flash suppressor and has been configured so it can be more quickly converted to infantry standard using an Egress Kit. The M240H is 41.2 in (1,050 mm) long, has a 23.6 in (600 mm) barrel, and has an empty weight of 26.3 lb (11.9 kg).
• M240L is a development of the M240B reduced in weight by 5.5 pounds (2.5 kg). The weight savings on the M240L are achieved by incorporating titanium and by using alternative fabricating methods for major components. A short barrel and collapsible stock are available.

MKEK has announced that a licensed version of MAG called PMT-76 or MFY-71 will be made under the National Machinegun Project (Turkish: Milli Makineli Tüfek Projesi - MMT).[23] 12 prototypes of PMT-76 were tested in 2017 and order of undisclosed number was put.[24] Current specifications are:[25]

• Barrel: 547mm
• Rate of fire: 600-900 r/m
• Range: 800m
• Mass: 8kg[26]