It sounds like you're making two assumptions, the barrels haven't been honed before, and that the bores are exactly concentric with the O.D.'s of the barrels. One or both assumptions may be incorrect. The only way to accurately determine wall thickness is to get the walls measured with a guage designed for that purpose. Personally I'd send the barrels away to get objective data and then make an action plan based on what I found out. Silvers

I AM SILVERS, NOT SLIVER = two different members. I'm in the northeast, the other member is in MT.