Fabrique Nationale Mk 46 LWMG

History of the Fabrique Nationale Mk 46 LWMG

In the early 2000s, USSOCOM (United States Special Operations Command) began a program to replace its long-standing Mk 43 Mod 0 (LMG) light machine gun. The Mk 43 is a specialized portable form of the Vietnam-era M60 General Purpose Machine Gun (GPMG) through the M60E4 variant, which retains gas operation and the 7.62x51mm NATO belt cartridge.

To increase the reliability of the M60 series, the Mk 43 gained an iron sight, a foldable bipod and a front vertical handle for extra grip. However, reliability was never really addressed and more modern systems required greater portability. This led to the "Light Machine Gun" program, led by the U.S. Naval Special Warfare Command (US NSWC), in collaboration with the Belgian National Fabrice Group, which produced an offshoot of the successful M249 SAW (Squad Automatic Weapon).

Based on the Fabrique Nationale Minimi family. The new product became the "Mk 46 Mod 0", a gas-powered automatic weapon, fed by the American M13 decay belt, and chambered for the 5.56x45mm NATO cartridge.

Likewise, the larger Mk 48 was simultaneously developed for special forces and chambered for the larger rifle caliber 7.62x51mm NATO cartridge.

The Mk 46 is exclusively based on the M249 SPW (Special Purpose Weapon) variant of the M249 series. The M249 SPW has a shorter barrel and front end, and lacks the standard carry handle, vehicle mount and magazine well of the original M249 product, lightening the design somewhat, making it more portable.

Unlike the SPW with its folding stock, the Mk 46 featured the moulded shoulder stock of the original M249 production model. MIL-STD 1913 rails were added (on the sides and bottom of the front end and along the top of the receiver) to extend the tactical nature of the weapon and allow various optics and accessories to be attached as needed.

An optional bipod can be mounted in front of the front baffle/heat shield to provide the additional frontal support needed to suppress fire.

The M46 action is based on open bolt operation and has a replaceable barrel assembly to prevent overheating and subsequent rupture. The weapon has a non-reflective black finish to protect the operator from flashes, while the bipod is constructed of lightweight and durable titanium to withstand the abuse of the modern battlefield.

The case itself is a formed steel frame construction, while the barrel is hammer forged steel with hard chrome plated holes (as is the inner cavity). The hips are made of lightweight polymer and are ergonomic. Optionally, a telescopic metal stock can be installed, which includes a hydraulic recoil buffer system and a non-slip butt plate.

Trigger guard is oversized for use with gloves. A carry handle mounted on the heat shield is optional.

The Mk 46 provides special operators with a high-capacity, compact, portable and adaptable autonomous weapons system. Its belt-fed nature means the Mk 46 operator can deliver massive amounts of fire from a distance through direct contact and suppression fire, further enhanced by available sights and optics. The use of 5.56x45mm ammunition also represents a logistically friendly addition to the M4 carbines and M16 assault rifles currently widely used by the US military and other countries. Additionally, the larger Mk 48 itself can complement the Mk 46 when the larger 7.62x51mm rifle caliber cartridge and its penetration at longer distances are required.

The Mk 46 has proven to excel in extreme conditions both in the wild and in urban environments.

The Mk 46 has an effective range of 800 meters against point targets and a maximum range of 1,800 meters against area targets. The system has an overall length of 36.22 inches and a total curb weight of 15.44 pounds. The listed cyclic rate of fire is 730 rounds per minute.

Currently, USSOCOM is the only approved Mk 46 LWMG operator. The MK 46 Mod 1 is an updated version of the original Mk 46 Mod 0 model.

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