A variant of The 1954 Model 39, Smith & Wesson attempted to market this Handgun as a replacement for The M1911A1 .45 Cal. Automatic Pistol. The Military declined a 9mm Pistol at the time. In 1955, it was marketed to several State Police Agencies. However, with America’s involvement in Vietnam, a variant was accepted. This was The Mark 22, Model O. Adaptable with a Noise Suppression Device (“Silencer”), the Handgun was manufactured exclusively for The US Navy SEALS as their initial issue sidearm. Weighing just 1-pound, 7-onces, it featured a 14-round ammunition Clip, and was effective at 200-yards. The primary goal of The Mark 22 was it’s ability to target Enemy Sentries (both Human and Canine). As a result of it's use as such, it was nicknamed The "Hush Puppy". Effective, it would remain in use throughout The War.