This is 50-70 caliber centerfire U.S. Trapdoor Springfield rifle. The serial number is 42203 and is numbered on the barrel and receiver. The lock is dated 1863 and breach block is dated 1870, with U.S. and the eagle proof mark. The barrel and iron mounting were finished in the white. The lock, breechblock and receiver have 40-45% case colors. There are two nice Inspector stamps on the left side of the wood stock. The mechanical function is very good crisp and tight. The bore is good plus to very good with nice rifling and light frosting at the muzzle.