Yes, those are "black powder" rifles, in that they were originally designed for use with black powder, and were so used until smokeless powder was developed.. But they are NOTmuzzleloaders, they are breech-loading cartridge arms, and both are able to fire the LOW-PRESSURE factory-loaded .45/70 fixed ammunition (405-grain bullet, MV 1320 FPS) that is loaded with smokeless powder. However, NEITHER the 1873 Springfield nor the .45/70 cartridge Sharps are capable of using paper cartridges. The Civil War era Sharps used paper cartridges and percussion caps. It was a .54 caliber, and could NOT fire metallic cartridges!

Neither the Sharps nor the Trapdoor Springfield should ever be fired with any of the current, high-performance .45/70 smokeless powder ammo that is made for the Marlin 1895 Lever Action or the Ruger No. 1!