Okay. Actual test I was part of: We fired 6,000 rounds through both a base M16A4 and a proposed change (sorry, can't say). While half the test group used one type, the other half used the other. Then, we switched. That's right, 12,000 rounds through both styles of M16. I had TWO malfunctions the entire time... ONE was caused by a bad magazine on the first day. The other, was MY fault. I did an 'overzealous' chamber check with 'cold-numbed' hands and ejected a round.
So to sum it up: I fired 11,998 of 12,000 rounds and both unfired rounds were NOT caused by the weapon. We sprayed the bolt and carrier down with squirt of CLP every 120 rounds, and cleaned the bolt, bore, and carrier every 600. The rifles were cleaned (to my standard) only once, at the end of the test.
Trigger control: The skillful manipulation of the trigger, which causes the weapon to fire, while maintaining sight alignment and sight picture.