So I spent five hours reading everything I could about Blackpowder pressure levels for period ammo. I was hoping for a straight forwards answer like service pressures for modern nitro proofed guns but none seem clearly defined. There is a lot out there, but much of it has little fact basis. Just the usual Damascus is unsafe to shoot rants and Black will eat your barrels myth. From what I see the default period service pressure is in the 5-6,000 psi range. There are examples under 5,000 but just as many or more above.
The goal is a safe, sane, nitro for Black load. My default Black powder pressure point looks to be in the 5,00-6,000 psi. Out of concern for the wood velocity will be under 1150 more towards 1050-1100 FPS and payload of one ounce or less. Pattern boards will help decide what loads seem best. Glad I have 30+ pounds of PB and several pounds of other discontinued powders to work with. I have a Westley Richards, Bar in Wood, hammergun double which ought to be a fine dove gun this weekend if I get the shells loaded. Off to the loading bench.
