jakes10mm - hmmmm, those are good questions. Do you have experience with BP? Did you get any feedback from the Single Action Forum about loads, bullets, lube with BP, fouling, etc when you use BP or substitutes in a smokeless cartridge firearm???
Down in the forum on The World of Blackpowder Shooting there is a thread on BP loadings for the 44 mag where they talk about lubes, wads and the like, and I don't know if that would help or be of interest to you.
From what I have read lately, a good BP load should be able to do the job at the ranges you indicated but I wonder how much power your loads would have. Articles on the use of the Pyrodex pre-formed pellets indicate that the 30 grain pellets give excellent consistency and accuracy out to 25 yds but it didn't sound like they had a whole bunch of whoppin' big power or eye catching velocities.
You will be shooting a Blackhawk which should have all the strength you need for a hefty BP load. The original loading for the 45 Colt was 40 gns of BP in the old balloon head cases - I don't know if you could stuff 40 gns into a modern case, maybe 38 grains and I don't know what ballistics that load would provide with, let's say a 250-255 gn bullet - hopefully close to 900'/sec, but from a longer barrel - 7.5" - I believe. I would think that you would need the extra barrel and velocity to get that bullet out there to do enough damage to take the animal at that range.
I believe one original capabilities of the 45 Colt cartridge for the Cavalry (7.5" bbl) was the requirement that 'it faults a horse at 100 (?) yds', meaning that it would cause the horse to stumble and fall when hit by that original BP load at that distance. Even if it was only 50 yds, a horse is so much bigger than a whitetail that I think you should be able to do what you want with a BP load and whitetail at the ranges you mentioned. HTH. Mikey.
