This is one of the cartridges shown in Foster’s Winchester’s “Forgotten” Cartridges, 1866-1900 and was part of four different cartridges developed by Winchester around 1875. The 56/45 shown here had a paper patched bullet, whereas the .50/40 cartridge was Milbank primed. The other two were the .56/42, and the.50/38 but no further information is known about these and if a rifle for any were actually made.
