in the 1870s the 3¼-inch cartridge was necked down to .45-inches to create the .500/450 magnum black powder express which in turn, when loaded with cordite, became the .500/450 nitro express. after the british government's 1907 ban of .450 caliber ammunition to india and sudan, the .500/465 nitro express and the .470 nitro express were formed from this cartridge.