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 a new facility and began experimenting with a new cartridge design more suitable than the .22 Short that it had been using. At the same time, the company's design was being infringed upon by other manufacturers which led to numerous lawsuits filed by Rollin White. In many of these instances part of the restitution came in the form of the offender being forced to stamp "Manufactured for Smith & Wesson" on the revolvers in question. White's vigorous defense of his patent caused a problem for armsmakers in the United States at the time as they could not manufacture cartridge revolvers.