M249 SAW
The licence-produced M249 is a version of the FN Herstal Minimi light machine gun with ergonomic and other modifications to meet US military specifications and manufacturing techniques. The main visual difference is the heatshield above the barrel. It is employed as the squad light machine gun in US Army and Marine Corps service.
Belt feed for the M249 involves 200-round belts using the M27 link, loaded into a plastic container. Rounds are fed with a ratio of four M855 ball to one M856 tracer, although special training packs using M855 ball rounds only are provided for areas where tracer is prohibited for fire-risk reasons.
During 1995, the US Army type-classified the M5 collapsible butt-stock for the M249. Several thousand of these were procured direct from FN Herstal. The US Army Rangers use the short (381 mm) barrel; this model is also used with the M5 collapsible butt-stock. Adoption of the short barrel for other units is planned.
Planned modifications for the M249 included a blank-firing attachment, optical sights (FY99) and a mounting suitable for installation on the High-Mobility Multipurpose Wheeled Vehicle (HMMWV) series. Other planned enhancements included armour-piercing ammunition, a feed tray cover with an integral Picatinny rail (FY99), mounting surfaces to accommodate a variety of combat accessories (FY02) and an ammunition assault pack. A collapsible butt-stock is also expected to be introduced into service.
Specifications:
M249 SAW
Cartridge: 5.56 × 45 mm
Operation: gas, firing fully automatic
Locking: rotating bolt head
Feed: 200-round M27 link belts or 30-round magazine
Weight: 6.85 kg; barrel, 1.7 kg
Length: 1.04 m
Barrel: overall, 523 or 381 mm (see text)
Rifling: 6 grooves, rh, 1 turn in 178 mm
Sights: fore, semi-fixed hooded post, adjustable for windage and elevation; rear, aperture, adjustable for windage and elevation
Sight radius: 490 mm
Muzzle velocity: 915 m/s
Muzzle energy: ca 175 kgm
Rate of fire: cyclic, ca 750 rds/min
Max range: ca 2,000 m; effective, up to 1,100 m
