Shotgunjones I think you are exactly right. So we have to just base it on what pressures we can determine Black powder shells of the day would generate. Thanks to Drew there are several different known Black powder pressure loads from the period and from that I think a basic load of 5-6,000 psi is going to be my safe pressure load. In fact I loaded 50 tonight for Dove this Saturday. My 150 year old Westley Richards is going to get a workout along with my Lab of color.