U.S. Springfield Trapdoor .45-70 Carbine breech block marked Model 1884, lock plate marked "U.S. Springfield", serial number 507482, visible 1890 cartouche, and "P" proofmark above "C.B.", butt plate
U.S. Springfield Trapdoor .45-70 Carbine breech block marked Model 1884, lock plate marked "U.S. Springfield", serial number 507482, visible 1890 cartouche, and "P" proofmark above "C.B.", butt plate marked "U.S.", 23-3/4 in. barrel,