Ta mate,

Mine's a Henry F/B 1868? patent with a straight stock, cranked lockplate and stalking safety in front of the RHS hammer. It's elsewhere ATM being restocked to the original but from memory the proofs are 440 with standard BP proofs (no powder charge stamped) with enough lede for the standard 3 1/4" case with a 350 grain pill to chamber easily with HEAPS of clearance for a 3 1/2 OA case length, thus I guess it's a 500/450 Magnum BP with a standard 140 grain BP load. It may well be a hybrid case (not having much of a step down/ bottle neck) and I do take Wal's comments on chamber variations in Vol 1 as of value. I estimate mfg date around late 1880s as the S/N is 6649.

Currently I load as much FFg C&H (cracker powder 130 grains?) as I can fit to a crush fit with a thin wad and a 9 grain charge of pistol powder above a magnum primer. Wrights book is a guide but I'm anxious to keep to safe working pressures if I go NFB.

BTW mine weighs 7 1/2 lbs.