Hidden between futuristic helicopters and tracked Strykers at AUSA was the AAI Corporation booth, at which were a lot of UAVs and a few light machine guns that looked like SAWs. In fact, they had a regular SAW on display, and a lot of people seemed to walk by without noticing any differences. Your eagle-eyed reporter did, in fact, notice a difference - perhaps the fifth or sixth time he strolled by - and stopped to take a closer look.
What was on display was the LSAT (Lightweight Small Arms Technologies) program, which has been in development by AAI and Picatinny/JSSAP for a number of years. This is a program that's been publicly discussed before, but recently passed some high-volume testing and is getting a lot closer to potential real-world use.
In a nutshell, it's a lighter weight light machine gun that fires lightweight ammunition. If that doesn't impress you, try this: the standard LSAT model weighs 9.4lbs, almost half what an M249 weighs (17.6lbs for the regular version). The ammunition is 40% lighter, too, meaning that a 100rd "nutsack" of the polymer cased telescoped ammunition weighs just over 2lbs, instead of 3.3 for regular brass cased 5.56. Still not impressed? Well, at 30.6lbs, the LSAT LMG with 1000 rounds of ammunition weighs 2.8lbs less than 1000 rounds of 5.56 and no weapon. It's an intrepid SAW man who carries four boxes in addition to the one attached to his weapon, but the fact remains that this system offers an impressive weight reduction.
If you noticed the words "polymer cased telescoped," you're probably thinking that this is some fancy lab program that will never work in the field, and that it was really inconsiderate of me to get your hopes up with the siren song of lightweight gear. In fact, this program has been successfully demonstrated at Technology Readiness Level 7, which is government-speak for "the prototypes work in field tests." This included eight prototypes firing 25,000 rounds over a period of three weeks at Fort Benning.
In addition to the cased telescoped ammunition, AAI is working on caseless ammunition that's even lighter and significantly more compact - compared to 5.56, the cased telescoped takes up 12% less volume; the caseless stuff has 40% less volume.
The prototype LMGs themselves feature some interesting technology such as a rotating chamber with in-line, push-through feed. What that means is that the chamber isn't integral to the barrel. It rotates off to the side, where the incoming cartridge pushes the spent case forward and out of the weapon. This separate, rotating chamber also helps deal with heat issues that have plagued polymer cased ammunition in the past. For clearing purposes, or if a spent case needs to be removed from the chamber and the incoming round doesn't do the job, there's an integral, spring-loaded rod that can be pushed all the way through the chamber. It's also important to note that the chamber is fully supported.
This program has been teasing infantrymen since 2004, but it looks to be impressively close to some real-world use. The lighter weight will certainly be nice for grunts. Unless their commanders elect to have them carry 2000 rounds just because they can.
