.44 Rimfire. 7.5" barrel length. SN: 3010. Nickel plated refinish overall including small parts with repaired simulated ivory grips. Single action loading gate revolver mounting rear notch and front blade sights on the ends of the barrel and built using the wedge pin frame design. The left frame displays the two line patent reading -PAT. JULY. 25. 1871-/-PAT. JULY. 2. 1872.- with the barrel address reading in a single line -ADDRESS COL. SAML COLT NEW-YORK U.S. AMERICA-. Mounts the externally sprung loading gate and Army size steel gripstraps of the later production run. The serial numbers match on the principal components including the arbor pin. The loading gate shows the assembly number 1562, and the replaced spring wedge pin is numbered 74528. Though outwardly resembling the earlier Richards and Richards-Mason pattern of cartridge converted revolvers, the Model 1871-72 Open Top revolver was manufactured from new production parts, making it Colt's first purpose built full size cartridge revolver (the smaller Cloverleaf and Open Top Pocket revolvers both entered production earlier). Chambered in the popular .44 Henry Rimfire cartridge, the revolver offered buyers an excellent companion to the repeating rifles offered by Winchester in the same instant. However, thanks to the development of the famed Single Action Army type, the Colt Open Top's production run lasted for just under one and a half years from February of 1872 to June of 1873 with less than 7,000 manufactured in total.