In response to Keith's questions. I took a closer look at the barrels. While the majority of the barrels look good, the area that would be considered the chamber have either buildup of something or corrosion. Need to clean that are up. In looking at the barrels, I can see that there is a taper and no step at the end of the chamber. If I run a steel rule in, it appears to be flat for about 2 15/16" and then a taper starts which runs out to the bore diameter at about 3 1/4".

More later, I'm sure.
Kirk