I have been getting an military action ready. for a new barrel, bent bolt etc.
I noticed that if I were to drill the front receiver ring I would be into the threads.
the question is when should the holes be drilled and taped, before the new barrel is installed or after.
thanks hivelosity

I remove the barrel and strip the receiver, then drill & tap and do all machining such as radiusing the rear bridge. It is a lot easier to drill& tap with no barrel in place! I drill & tap in the vertical mill, using a special jig I made that gets the holes straight and perpendicular to the receiver axis.

John: Would you share how you made you jig?
I have made 1 to date but had a hard time getting the pilot holes on center. I plan on using a mill next instead of the drill press.
hivelosity