IIRC during the Indian Wars the soft copper cartridge cases used in the 45-70 were the source of a lot of problems, the extractor would cut through the rim leaving the body of the case stuck in the chamber. The troops were not issued a broken case extractor, it was said a cavalry trooper then could cuss for 20 minutes straight without repeating himself. The cartridge case was simply too new an idea-First Generation, to use current terminology-to be completely relied on.
IMHO TOO many things would have to been invented at the same time by ONE
person-invented AND perfected AND the manufacturing procedures and tools designed and manufactured-for a practical semi-or fully automatic weapon to have been adopted then, and as others have noted black powder is NOt a suitable propellant for such use.