Don,
I thought that was the case with those. I have patched those with different papers and check the 2 diameters a number of times and I usually end up scratching my head and thinking, "How's that going to work?", but that is thinking as a target shooter.
All my BPCR hunting in the past has been with my .50-70 and a grease groove bullet that carried a good amount of lube and I was able to chamber and shoot several shots with no more than blowing into the breech if needed. I only actually fired follow up shots on two occasions and all shots hit their mark.
I will detail out a drawing based on your bullets before I shoot then all up so if they work in my rifle I'll be able to have a mold made for that bullet.
What paper do you use on those bullet when "shooting dirty"?