Smith & Wesson Model 39

The Smith & Wesson Model 39 is a semiautomatic pistol developed for the United States Army service pistol trials of 1954. After the Army abandoned its search for a new pistol, the Model 39 went on the civilian market in 1955 and was the first of Smith & Wesson's first generation semi-automatic pistols.
A modified version saw limited use with Naval Special Warfare units as the Mk 22 Mod 0.