Thanks for the advice..I am leaving it be for now. I had a good time with it a over at creekside shooting it as is. alleycat got any pics of that blue target after you got her sighted in?Sorry I'm jumping into the thread late. I found out first hand Bushmaster presses in the sight block pins, so whatever free float system you use, bank on not getting the sight block off without something a lot more than a hammer and punch. Midwest's free float quadrail that clamps on the existing barrel nut by cutting off the delta ring would be a good choice.