This Colt Model 1855 Military Rifle was made with five-shot fluted cylinder and 37 1/2-inch round barrel with semi-octagonal section at the breech. Colt manufactured 8,075 .56 caliber Military Rifles; 4, 825 of these rifles had the long, 37 1/2-inch barrel. The rifle has a period tin-plated finish with blued, three-leaf, rear sight and walnut stock and forearm. The rifle front sight serves as a lug for a socket bayonet. The rear sight leaves are calibrated for 100, 300 and 600 yards. The buttplate has a sliding trap for a cleaning rod extension. The top strap is roll-stamped: "COL. COLT HARTFORD CT. U.S.A.". "PATENTED SEPT. 10th 1850" is stamped in one cylinder flute. "COLT'S PATENT/Nov. 24th 1857" is stamped on the left side of the frame above the side plate. The serial number, "4164" is visible on the lower receiver tang, the bottom of the frame and on the heel of the buttplate. All of the visible serial numbers match. Several Federal regiments were armed with Colt Model 1855 Revolving Rifles during the Civil War.

Very fine as period plated. The rifle retains 95% of the unique tin plated finish. The plating on the inside of the frame has some moderate flaking but the majority of the finish is smooth and in very good condition. The rear sights have most of the blue finish. The stock and forearm are in very good overall condition with minimal handling wear. All of the markings are sharp. The action is tight and functions well. This is a unique example of an extra length barrel, tinned finish Colt Model 1855 Revolving Military Rifle that was quite possibly from a Hartley & Graham display board!