Smith & Wesson "N" to the largest .44 Magnum type frame. In 2003, the even larger "X" frame was introduced for the .500 S&W Magnum. Most Smith & Wesson revolvers have been equipped with an internal locking mechanism since the acquisition by Saf-T-Hammer. The mechanism is relatively unobtrusive, is activated with a special key, and renders the firearm inoperable. While the lock can simply be left disengaged, most gun enthusiasts prefer "pre-lock" guns. In 1953 the U.S. Army was looking for a pistol to replace the Colt 1911A1. To obtain a bid from the U.S. Government, Smith & Wesson began working on a
Smith & Wesson Model 3 Wesson–made revolvers (which Smith & Wesson had already produced), and delaying (or refusing) payment for the handguns that had already been delivered. The U.S. Army adopted the .44 S&W American caliber Smith & Wesson Model 3 revolver in 1870, making the Model 3 revolver the first standard-issue cartridge-firing revolver in US service. Most military pistols until that point were black powder cap and ball revolvers, which were (by comparison) slow, complicated, and susceptible to the effects of wet weather. In 1875, the US Ordnance Board granted Smith & Wesson a contract to outfit the military with Model 3 revolvers incorporating