HighRez

The barrel is .800 at the muzzle, then steps up to .941 about 4" back. It is this step up "shoulder" that stops the .936 gas block. It is a 2 set-screw PRI steel low profile block.

Just got my steel PRI .936 gas block. Wouldn't go over the barrel shoulder on the test fit. Calipers revealed that the barrel is actually .941, so I need to remove .005 from the inside of the block. I tried a brake cylinder hone ... all it did was polish it up slicker 'n Owl Poop. Any suggestions for a way to get this done without resorting to machining? Thanks guys.

Thanks Robo ... I appreciate it. Now if I could only find a bolt carrier group I could put this puppy together ;D

I know there's been a lot of gas block posts here, but I've been unable to find an answer to my question. I'm putting together a project that has a rifle length gas system and requires a .936 gas block. First, are AR-15 and LR-308 gas tubes interchangeable? Second, will I need a straight gas tube or one with the conventional bends? Thanks for the help. Bob