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 debuted in two varieties: the M&P15 and the M&P15T. The two are basically the same rifle, chambered in 5.56 NATO, with the T model featuring folding sights and a four-sided accessories rail. These rifles were first produced by Stag Arms but marketed under the Smith & Wesson name. Currently Smith & Wesson makes the lower receiver in-house while the barrel is supplied by Thompson/Center, a S&W company. In May 2008, Smith & Wesson introduced its first AR-variant rifle in a caliber other than 5.56 NATO. The M&P15R is a standard AR-15 rifle chambered for the 5.45×39mm cartridge. In 2009, it