Smith & Wesson Model 39
The Smith & Wesson Model 39 is a semi-automatic pistol chambered in 9×19mm Parabellum, featuring a lightweight aluminum alloy frame, double-action/single-action trigger mechanism, and recoil-operated locked-breech action.[1][2] Introduced in 1955, it was the first double-action semi-automatic pistol designed and marketed in the United States, with a 4-inch barrel, overall length of approximately 7.44 inches, unloaded weight of 26.5 ounces, and an 8-round single-column detachable magazine.[2][3] Developed in the early 1950s for U.S. Army service pistol trials seeking a lighter alternative to the .45 ACP M1911, the Model 39 drew inspiration from the Walther P38's DA/SA system and adjustable sights but was not selected for broad military adoption.[4][5] Despite its single-stack magazine limiting capacity compared to later designs, the pistol's ergonomics and reliability contributed to its use by specialized units, including a suppressed variant known as the "Hush Puppy" employed by U.S. Navy SEALs in Vietnam for silent guard dog neutralization and reconnaissance.[6][4] Production continued until 1982, influencing the development of subsequent Smith & Wesson models like the higher-capacity Model 59 and establishing features commonplace in modern compact service pistols.[4][7]