Thanks to both of you, Mike and Miller.

Miller while I have a lot of confidence in the skill of my smith, what you suggest about using a SAAMI spec gauge sounds likely. And I really appreciate the link, Mike.

Seeing as I was intending to shoot 2 1/2' though it, sounds like I should be okay. I'm guessing it's already had a whole lot of 2 3/4" run through it by previous owners who just assumed.

The world cries out for such: he is needed & needed badly- the man who can carry a message to Garcia