AAI Corp continues to develop caseless, telescoped ammunition and machine guns to fire it under the United States Joint Service Small Arms Research Program Office’s (JSSAP) Lightweight Small Arms Technologies (LSAT) program.  The caseless, telescoped ammo and gun developed by AAI under this program, was first mentioned at The Firearm Blog in 2010.

In a parallel development program, the company developed a polymer cased, telescoped round.  The cased round is a “full polymer cartridge” that claims a 40% weight reduction when compared to metal cased ammo.  The rounds also feature a 12% volume reduction, meaning the same sized pouch will carry more ammo and still be lighter than conventional ammunition.

According to AAI, more than 50,000 of the cased, telescoped rounds have been fired.  Presumably, this includes the US Army 2011 testing.

AAI has two belt-fed guns, one a full size machine gun comprable to the M249, and a second compact variant with a short barrel and folding stock.  The company states the guns use a rotating chamber to “…[provide] in-line, push-through feed and ejection…”

Currently, the cased, telescoped ammo is in 5.56mm, and the same technologies are being used to develop a 7.62mm round.