LSAT light machine gun

LSAT light machine gun
A U.S. Army soldier performs a test shooting of a prototype cased telescoped light machine gun in 2010.
Type	Light machine gun
Place of origin	United States
Production history
Designer	AAI Corporation
Designed	2003 onwards
Manufacturer	TBD
Unit cost	≤US$3600
Produced	Earliest: 2010
Variants	Cased telescoped ammunition firing variant Caseless ammunition firing variant
Specifications
Weight	9.8 lb (4.45 kg) empty (cased telescoped variant) 9.9 lb (4.5 kg) empty (caseless variant)
Length	36.1" (917 mm) (stock retracted)
Barrel length	16.5" (418 mm) standard 12.5 in (320 mm) compact
Cartridge	Cased telescoped ammunition LSAT caseless ammunition
Caliber	5.56 mm (at present)
Action	Gas-piston; push-through feed-and-ejection; open, swinging chamber
Rate of fire	≈650 rounds/min
Muzzle velocity	920 meters/sec
Effective firing range	≈1000 m
Feed system	100 (cased telescoped) or 150 (caseless) round soft pouches of full-loop-polymer linked, disintegrating belts
Sights	optical, future variants to include advanced tracking and acquisition

The LSAT light machine gun, of the LSAT (Lightweight Small Arms Technologies) program, is a developmental, powerful light machine gun (LMG). The purpose of the program was to develop a lighter, yet very reliable LMG. The program was initiated in 2004, when the Joint Service Small Arms Program (JSSAP) challenged the American defence industry to develop a lighter small arms and also design lighter ammunition. The LMG provides a major reduction in weight over legacy weapons, as well as improvements in other areas, such as controllability and reliability. As of 2008, it had two configurations, one that fires cased telescoped ammunition, and one that fires caseless ammunition. After further research and development into both technologies and the guns that fire them, one of the two variants was to be chosen for production. By May 2015, 85,000 cased-telescoped rounds had been fired through 10 test weapons, with testers claiming the weapon had gone as far as it can go until the Army decides if it wants to make it a program of record.

Development began with the two types of weight-reducing ammunition, and a light machine gun to serve as a testbed and technology demonstrator. Use of an LMG for this purpose is notable, considering its greater technical complexity than infantry rifles. The use of advanced computer simulations to accelerate development may have mitigated this, and the less significant LMG succeeds at being less conspicuous to unwanted media attention. For development, the use of extensive computer simulation and modelling reduces both time and expenditure for prototyping and testing. The program also uses a 'spiral development' approach, whereby the weapon and ammunition is rolled out in stages or 'spirals', each stage producing a new version that is an improvement on those from previous spirals. A competition down-selected the design concepts of various companies to leave an AAI Corporation-led team of companies as the developers of the weapon system. The cohesive team of companies is combined with government support to ensure success. The parallel development of the two ammunition types meant that, if the caseless ammunition effort succeeded, much of the development work gained with the composite cased weapon could be applied to it, and, if it failed, the composite-cased version was likely to succeed on its own.