Hoorah ! The .50-70 Govt. is also one of my favorites, the first centerfire military rifle cartridge of the USA in 1866, maybe the first in the world ? Buffalo Bill killed plenty of bizon with his Lucretia Borgia so chambered.
I have a McNelly Sharps carbine replica .50-70 like Glenn Campbell used as a Texas Ranger in True Grit. It has a 1:18" twist by gosh, 0.512" groove. I could make use of your load in that if I ever need to punish myself.
My Custer Replica Rolling Block in .50-70 has a 24" twist and .510 groove. IIRC you are shooting a 1:22" twist. What BP charge are you using with that 530-grainer in the .50-70 Govt. ?
I will not be trying that in my 1867 vintage Trapdoor with 1:42" twist and .515"-ish groove diameter.
Ron aka "Rip" for Riflecrank Internationale Permanente NRA Life Benefactor and Beneficiary .458 Winchester Magnum, Magnanimous in Victory THE WALKING DEAD does so remind me of Democrap voters. Donkeypox.
