Can someone please tell me the wall thickness of an AR barrel with a 1/2-28 thread at the muzzle (top of thread to inside diameter)? I'm getting ready to pin and weld my comp and want to be sure not to drill through the wall.

 

I'm assuming its .500" minus .223", divided by 2 (.1385")?

 

Thanks.

Depends how you measure things. The diameter of the barrel at the threads is 0.5 inches. The bore diameter is .224 at the grooves. If you don't care about the measuring at the lands or worrying about the metal missing from the thread itself maths says the wall thickness of the barrel at that point is 0.138"

drill the brake off the barrel, then time it and just send the drill in lightly , then send the pin home

Drilled down .050" and TIG welded the pin in.  My rifle is much less dangerous now.