they slacked up on the milsurp rules since you cant get civilian M16's very easily or cheaply. there is no real way for them to get milsurp semis there arent any. so instead the set a list of rules to roll your own AR15 or buy one that qualifies. rock river arms A2 20" rifles qualify.
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent