Fifth model Burnside carbine manufactured from 1863 to 1865. The 5th Model differs in that it has a guide screw in the center of the right side frame allowing smoother operation as the breech rides in a corresponding groove in the breech block. The barrel was blued and fitted with a two-leaf, folding rear sight graduated to 500 yards. The buttplate, receiver, hammer lever and barrel band have a casehardened finish. The barrel tang, trigger guard, and breechblock had a high polish niter finish. The forend and stock are black walnut. The frame and lock plate have the standard two line Burnside marks including the 1856 patent date. There is a saddle ring bar and ring mounted on the left side of the receiver. The top of the barrel is stamped "CAST STEEL 1864" ahead of the rear sight. The serial number "11992" is located on the top of the frame and breechblock. Small "H" sub-inspector's markings are stamped on small components. Two clear script Ordnance inspection marks are stamped on the left stock wrist. A crude "JH" has been carved into the right side of the stock.