Thanks Jim and Jack, I'm still confused. I understand what you are saying Jim, whatever choke there is would be from the area before the choke. In this case it would be .718 and .719 on the Skeet's gage, and if you zero it at that reading, you would read zero coming out the right barrel and -9 on the left barrel.
To make things more confusing, from the breech, a .724 plug gage went in 22 7/8" and stopped in the right barrel, a .726 went in 9 3/4". I'm going to make a .718 tomorrow and see how that fits.
