Colt Model 1871-72 Open Top

Did You Know?

• Cimarron Firearms of Fredericksburg, Texas, imports a replica of the Open-Top revolver based on an antique example reverse-engineered by Uberti.
• The replica differs from the original by having a safety placed on the hammer.

Development

Previously, the company had only practiced Richards-Mason conversions, and it continued converting muzzle-loading percussion revolvers into rear-loaders until 1878. In 1871, Colt's patented at least two rear-loading revolvers using metallic cartridges: the Colt House Revolver and the Open Top. The House revolver entered production that same year, but the Open Top did not start production until 1872, although a pocket version of the Open Top—a completely different design—went on sale in 1871 as the Colt Open Top Pocket Model Revolver. Mason introduced innovations including a breech-loading cylinder, a unique frame, cylinder and barrel with parts non-interchangeable with older percussion pistols, and a rear sight moved to the rear of the barrel. Chambered in .44 caliber, the gun was submitted to the US Army for testing in 1872 but was rejected; the Army requested a more powerful caliber with a stronger frame. Mason then redesigned the frame to incorporate a topstrap similar to Remington revolvers, placed the rear sight on the rear of the frame, and consulted with Richards on other improvements. The first prototype of the new gun remained in .44 rimfire, but the final design was chambered for the .45 Colt cartridge. Early Open Top revolvers were marked COLT'S/PATENT; later models bore the "Two July" patent marking, also found on 1851 Navy, 1861 Navy, and 1860 Army conversion revolvers, as well as on very early Colt Single Action Army revolvers.