From the Vault: Colt 1860 Army Revolver Thuer Conversion

We had no trouble persuading Brownells Gun Techs and resident firearm historians Keith Ford and Steve Ostrem to visit to Rock Island Auctions, so they could show us a Colt Model 1860 Army Thuer Conversion revolver. The Thuer Conversion turns the cap-and-ball 1860 Army into a front-loading metallic cartridge revolver. Why front-loading? Because Smith & Wesson owned the patent on the revolver cylinder with bored-through chambers. The patent's original holder, gunsmith-inventor Rollin White, offered to sell it to Colt, but they passed. Smith & Wesson did not and hence was the sole LEGAL producer of revolvers with rear-loading cylinders. Realizing its mistake, Colt tried to backtrack, and the Thuer Conversion enabled them to build a metallic cartridge revolver without violating S&W's patent.
Rock Island's Thuer Conversion 1860 Army is in superb condition and even comes with a few of the unique, tapered, centerfire cartridges. Steve demos how you load and - more interestingly - UNLOAD a Thuer Conversion revolver. Even more unusual, the gun itself served as a reloading press to reload the special cartridges! The gun was finicky to operate compared to a Smith & Wesson revolver, and every Model 1860 Thuer Conversion came with a standard cap-and-ball cylinder as backup. It was superseded by the Colt 1872 open-top rear-loading cartridge revolver, introduced soon after White's patent expired.