Stechkin automatic pistol or APS (Avtomaticheskiy Pistolet Stechkina, Russian: Автоматический Пистолет Стечкина) is a Russian selective fire machine pistol. It bears the name of its developer, Igor Stechkin.
The Stechkin automatic pistol was originally chambered for 7.62×25mm Tokarev. Stechkin changed the pistol to the 9 mmcaliber used in the new Makarov pistol (PM), as it became clear that this cartridge was set to become the new service ammunition for handguns of the Soviet Army. In 1951, both the Makarov and Stechkin were introduced into the Soviet military arsenal, replacing the aging Tokarev pistol (TT-33). They have little in common except for the simple unlocked blow-back mechanism.In contrast to the Makarov, the Stechkin has an automatic fire mode, which is selected using the safety lever. In burst or automatic fire, the pistol should be fitted with the wooden or metal shoulder stock; otherwise, the weapon becomes difficult to control.