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 645 4506 had a rounded trigger guard profile, which replaced the earlier squared profile inherited from the 645. The 4506 was produced from 1988-2001. The S&W 645 was used in Miami Vice by the character Vice Detective Sonny Crockett in seasons 3 and 4 of the TV series. Smith & Wesson Model 645 The Smith & Wesson 645 and Smith & Wesson 745 are second-generation semi-automatic pistols which predates Smith & Wesson's 4500 series of handguns. The S&W 645/745 is chambered for the .45 ACP cartridge. The S&W 645 is constructed almost entirely from stainless steel and is thus extremely resistant