The Wu Silent Pistol, officially the Windurger No.2 Silent Pistol, was a special tranquilizer pistol that replaced the Mk22 Hush Puppy as the standard side arm for the Militaires Sans Frontières, and later the Diamond Dogs. It was a pistol that fired small-caliber tranquillizer rounds. There were two known models of the Wu Silent Pistol; one with a built-in suppressor used in the mid-1970s, and another with a detachable suppressor that degenerated, used in the 1980s. The former's overall design was meant to produce little gas or recoil, enabling its built-in suppressor to maintain its function indefinitely. To further limit noise, its rounds had a low muzzle velocity, resulting in a short effective range.
During the 1980s the Diamond Dogs developed a lethal round conversion of the Wu Silent Pistol.
Behind the scenes
A golden version of the Wu Silent Pistol was revealed for Metal Gear Online 3, and will be available to those who purchases the Collector's Edition of Metal Gear Solid V: The Phantom Pain after the player reaches level 4. More accurately, it was a gold skin option for the Wu Silent Pistol itself. The gold skin appears to be based off of the .44 Auto Mag pistol, which was produced between 1971 and 1982, while the default model is based on the Ruger MK2, which was produced between 1982 and 2005.