William Mason and Charles Brinckerhoff Richards who had developed a number of revolvers and black powder conversions for the company. Their effort was designed for the United States government service revolver trials of by Colt's Patent Firearms Manufacturing Company and adopted as the standard military service revolver. Relative to period cartridges and most later handgun rounds, it was quite powerful in its full loading. By the end of , serial no. There was also a variant with a subinch barrel, without an ejector rod, unofficially called the "Sheriff's Model", "Banker's Special", or "Storekeeper".
Made in About as good as it gets. This is a beautiful gun with the factory engraving and the condition is just spectacular. All original blue, all original silver and all Frames have bright case colors. Grips are excellent Compare Colt U.