I lubed some 405 gr bullets I had and ran them through the .457"
sizer then loaded up 50 rounds of black powder cartridges for the .45-70. I weighed all the charges for the cases. I was surprised that a 70 gr by volume charge of Goex FFg weighed 63.5 gr on my scale. I rounded it up to an even 65 gr by weight.
Each charge was poured down a drop tube, a .060" veggie wad pushed into the case and then the bullet seated so it was .050" off the rifling. I had to use a veggie wad because otherwise I wouldn't have enough compression on the black powder. The way I calculated it I have about 3/16" of compression which should be good.
When I cast me some 500 gr slugs I will likely not need the wads.
All I need now is a day with no rain so I can try them out. This is my first effort at shooting black powder cartridges and I was doing tons of research on it.