you dont need black powder to shoot black powder, use somthing a lot cleaner like tripple 7, or if you want somthing more cheaper thats just like black powder and jsut as corrosive use pyrodex
I like the birds head grip on the M1873s and have a surplus Uberti birds head grip in the spares box. I'm actively looking for a cheap Uberti Cattleman to build into a 3" barrel Sheriffs Model piece sans ejector rod.