OT, but I know some of you can help Loaded some shells for my Martini Henry .450/.577 with about 90 grains of black powder (2F) and typical 480 grain lead bullet. Put some cotton filler and a wad in the neck to keep the powder from moving. Loaded them in nice jameson brass.

Some of the primers backed out on firing. I can't believe the pressures were too high. Any suggestions?

Also any suggestions on a smokeless load. I read some use IRM 3031. What about trail boss?

Jerry