The only reason I'm NOT buying one of these (well, the M5 version) to finish my fallen friend's M16A4 is that that would be one less, and one very BIG and important less, of his bring-back parts going into a weapon completed in his memory.

(Okay, with WA's new BS bans, piss be eternally upon all behind their enactment and all who support those traitors to their oaths, it's a spare upper to swap onto his M4, but y'all see my point.)