Ive got a bit of experience hunting with suppressors. Bolt guns are far far far superior to semiautos for effective sound suppression. Ar15 with suppressors are still quite loud due to the action itself slamming around and the gas system letting a lot of noisy gas out.
Most ar15 are just barely hearing safe with a suppressor.
If you go sbr 300blk ar15 i HIGHLY recommend getting a 30cal suppressor that has a qd function. That way you can move it easily from gun to gun. If you get a cheaper screw-on your stuck with only one thread pattern.
I can use my qd suppressor on any .308 or smaller diameter rifle excluding 22lr as 22lr will gunk a sealed suppressor to uselessness very snappy quick as you cannot remove the lead without a good soak in a mercury bath...
"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