depends on the diameter of you barrel. you will also need a A2 or A1 flash hider or equivelent to mount a bayonet. AR-15/M16 GAS BLOCK - Brownells
there are other versions thats just a quick google search
scroll down a bit to: 100-003-172
Single-Rail Gas Block w/Lug & Swivel
Mfr. Part: YHM9836A
"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
Last edited by JonM; 07-05-2011 at 10:48 PM.