This rifle falls into the serial number range (11000 to 61000) of the 50,000 Spencer carbines made in the Civil War period of 1863 to 1865. This particular rifle has a 29 3/4" octagon barrel marked "CAST STEEL" on the upper left rear flat and J. H. JOHNSTON / GREAT WESTERN GUNWORKS PITTSBURGH, PA." on the top flat. Both markings read from breech to muzzle. The top of the frame is marked with the standard three line address/patent date and the serial number is marked on the upper rear of the frame. The barrel gauges at 45 caliber with 6 grooves and is equipped with a dove tailed brass blade front and fixed notch rear sights, and a sling swivel base on the lower flat ahead of the forearm. Blue barrel and casehardened remaining parts, and mounted with a smooth forearm and straight grip stock with a crescent iron buttplate and sling swivel base.