LWRC International's M6 Individual Carbine chambered in 5.56 NATO is not only a premium AR-15, but it also includes the groundbreaking short stroke gas piston system developed pioneered by LWRC. The M6 Individual Carbine was developed for the US Army's individual carbine program. As a result, LWRC incorporated their outstanding short stroke gas piston with the standard M4/M16/AR-15 design to make a truly incredible rifle. If you are looking for the accuracy of the AR with the reliability of a short stroke piston system, then this is the rifle for you.