Jack, nothing removed from barrel length.
I'm confused, if you remove material from inside diameter, the balls in the gage would not compress, they would expand and give you a higher number, not a lower number, as seen with the area of choke.
Turning the o.d down gives you smaller, turning i.d gives you larger.

Am I missing something.

Last edited by JDW; 09/30/10 08:03 PM.
David