Keith J. I would have sent you an email but... I have one Bushmaster 1:9 22" that I whacked the threaded part off of and crowned. It is still shooting the same small groups after 1800 or so rounds as the day I finished the project. Near 1/4 inch at 100 yards with ammo it was happy with. I have chopped another , Colt chrome barrel 1:7 20" and am having great fun with it.
My question is, what is going to happen to my bobbed chromed barrels after ??? rounds? BTW, all my cut and crowned AR's shoot a good bit better than the stock ones including the Delta Elite H-Bar that I am happy to have but paid way too much for.
Mic, you should expect all of the lower parts, springs , etc. just make sure that they are AR parts and not M-16 parts. Not to say that anyone would ship you a M-16 trigger by mistake but it pays to know the difference.