Chiefly produced with 18 and 21 inch barrels, very few are known to have been made in this short barreled configuration. The serial number, "6" is visible on the upper and lower receiver tangs and on the underside of the barrel. The carbine has a walnut stock, with sling swivels and a sling ring mounted on the bottom and left side of the frame, respectively. Half-moon blade front sight and with three leaf rear sight graduated to 100, 300 and 500 yards. The stock has a solid buttplate. "COLTS/PATENT" is roll-stamped in two lines on the upper tang and "56 CAL" is stamped on the left side of the trigger guard. No Colt markings are visible on the cylinder.

Very good, showing a silver-gray patina with traces of the original tinned finish in protected areas. The serial numbers and caliber marking are clear, with faint Colt patent markings on the upper tang and the original markings on the frame, top strap and cylinder are not legible. The surfaces of the barrel and frame have some age discoloration but are smooth and free from pitting. There is light flash pitting on the percussion nipples and the rear face of the cylinder. Period revarnished stock, with moderate handling wear. The action is tight and functions well. This is a solid very good example of a scarce Colt Model 1855 Carbine in .56 caliber with 15-inch barrel and very low serial number.