FN MINIMI

The MINIMI (short for French: Minimitrailleuse; “Mini machine gun”) is a Belgian 5.56 mm light machine gun developed by the Fabrique Nationale (FN) company in Herstal by Ernest Vervier. First introduced in 1974, it has entered service with the armed forces of several countries, among them: Australia, Belgium, France, Canada, Italy, Indonesia, Malaysia, New Zealand, Thailand, Sweden and the United States (as the M249 SAW). The weapon is currently manufactured at the FN facility in Herstal as well as being license-built in Australia, Canada and the USA (by FN Manufacturing LLC). The MINIMI is configured in several variants, the standard model (as a platoon or squad support weapon), the Para version (for use with armored vehicle crews, helicopter pilots and parachute infantry) and the vehicle model (as secondary armament for fighting vehicles).

Design details

The MINIMI is an air-cooled machinegun that uses a gas piston operating system (with a long stroke piston) that is driven by expanding exhaust gases bled through vents in the barrel. The barrel is locked with a rotary bolt (equipped with two locking lugs), forced into battery by camming guides in the bolt carrier. It has a manually-adjustable gas regulator with two positions, normal and adverse. The adverse setting increases the cyclic rate and is used only in extreme environmental conditions or when heavy fouling is present in the weapon’s gas tube. The spring extractor is located inside the bolt, while the tilting lever ejector is contained inside the receiver housing. The MINIMI is striker-fired and the bolt carrier functions as the striking mechanism.
A British soldier from the Queen's Dragoon Guards fires an FN MINIMI support weapon.
A British soldier from the Queen's Dragoon Guards fires an FN MINIMI support weapon.

The weapon is fed from the left-hand side by disintegrating-link M27 ammunition belts, from either an unsupported loose belt or enclosed in an ammunition box (with a 200-round capacity, made of a synthetic polymer), attached to the base of the receiver or from detachable STANAG magazines, used in other NATO 5.56 mm assault rifles such as the M16 and FNC (magazine feeding is used only as an auxiliary measure, when belt-linked ammunition has been exhausted). The ammunition belt is introduced into the feed tray, the magazines are seated inside the magazine port (shut with a dust cover when not in use) located under the feed tray port. When a belt is in the feed tray it covers the magazine port. Likewise, a magazine inserted into the magazine well will prevent the simultaneous insertion of a belt. The pawl-type feeding mechanism is modeled on the system used in the MAG general purpose machine gun. The belt is moved in two stages during both forward and rear movement of the reciprocating bolt carrier. The feeding mechanism’s top cover features a device that indicates the presence of a cartridge in the feed path.

The light machine gun is fired from an open bolt. It has a push-button type manual safety installed in the trigger housing, above the pistol grip. In the “weapon safe” position it disables the sear mechanism.

The barrels used in the weapons have an increased heat capacity, feature a chrome-lined rifled bore (6 right-hand grooves) and are manufactured in two versions: with a 178 mm (1:7 in) twist rate (used to stabilize the heavier Belgian 5.56x45mm SS109 cartridge) and a 305 mm (1:12 in) twist (for use with American M193 ammunition). The barrels have a quick-change capability; they’re equipped with slotted flash suppressors and integrated carrying handles, used to transport the weapon and assist in changing-out a hot barrel.

The standard light machine gun version has a 465 mm (18.3 in) barrel and a skeletonized aluminum stock with a folding wire shoulder strap, the shortened Para model – a 349 mm (13.7 in) barrel and a telescoping metal stock, while the vehicle-mounted model has a 465 mm (18.3 in) barrel and does not have a stock or iron sights.

Both the standard and reduced Para variants are equipped with a fixed, folding bipod mounted to the gas tube and stowed under the handguard. The bipod can be adjusted in height and has three settings. The weapon’s highest setting with the bipod’s legs fully extended elevates the weapon to a height of 465 mm (18.3 in). The machine gun can also be fired from the Belgian FN 360° tripod or the American M122 mount using an M60 pintle.

The vehicle-mounted MINIMI is fitted with an electrically-powered trigger that enables it to be fired from within an armored fighting vehicle. Both the standard and Para models come with a rear sight (adjustable for windage) that provides a peep aperture for ranges from 300 to 1000 m in 100 m increments. An adapter can also be used that allows the use of standard NATO night and day sights. Standard equipment supplied with the MINIMI consists of: three ammunition boxes with a 200-round capacity each, a cleaning kit (stored inside the forearm), lubricant bottle, sling and blank firing attachment.

Variants

The M249 version of the MINIMI was adopted by the US military in 1982, and since 1984, production is carried out entirely in the US by a local subsidiary - FN Manufacturing LLC in South Carolina.

As part of the US military's M249 Product Improvement Program, the M249 was updated with: a new synthetic stock with a modified buffer assembly; a single-position gas regulator; a “birdcage” type flash hider/compensator from the M16A2; a polymer barrel heat guard; and a folding carry handle. As a result, the weapon’s weight increased to 7.47 kg (16.5 lb). Many of the PIP upgrades were later adopted by FN for the MINIMI Mk2 variant.
An Australian soldier with the F89 version of the MINIMI.
An Australian soldier with the F89 version of the MINIMI.

A lightweight variant of the Para with a Picatinny top cover rail adapter is known as the MINIMI SPW (Special Purpose Weapon). It had the magazine feed port removed to further reduce weight, and a railed MIL-STD-1913 handguard was used that enables the use of standard tactical accessories.

Another variant of the SPW requested by the US Special Operations Forces is the Mk 46 Mod 0 that incorporates a lightweight fluted barrel but lacks the magazine feed system, vehicle mounting lugs and carry handle. A railed forearm ensures modularity and mission-adaptability permitting the use of flashlights, vertical grips, and infrared laser designators. An improved variant known as the Mk 46 Mod 1 with an improved forward rail and lightweight titanium bipod has been adopted by the US Navy.

The MINIMI prototype was originally designed in 7.62x51mm NATO, and later redesigned around the 5.56 mm cartridge. When the USSOCOM issued the requirements for the Mk 48 Mod 0, the original plans for the MINIMI were retrieved and used to develop this new model. As a result of favorable reviews of the Mk 48 Mod 0 and increasing demand for a more powerful variant of the MINIMI, FN Herstal introduced the MINIMI 7.62 available in several different configurations.