Most reliable? That must be why even Americans want it replaced by Hk416s..The Colt is hands-down the most reliable and easy to use AR, and the sensible option to choose, yank or not. I think our guys should go to M4 Carbines. A great all-round weapon with minimal recoil. The 556 will be what's used as that's the Nato round. You can hit what you';re aiming at with a 556 though, the 7.62 round has way too much recoil to get a second shot on target, and forget FA fire.