Thank you Raimey for posting my pictures and guys for the interesting conversations.

I have cerrosafe on order to do a chamber cast. I slugged the barrels 6" down on the breech end and 2" down from the muzzle. Both areas mike at .510 groove dia. It's hard to measure the lands being an odd number and narrow. The best I can mike the length on the chamber to the first step is around 2.100" with touching the rifling at 3.100" Unsteady hands and bad eyes now. Hopefully a chamber cast will help