The Stechkin or APS (Avtomaticheskiy Pistolet Stechkina = Автоматический Пистолет Стечкина) is a Soviet selective fire machine pistol that is chambered in 9×18mm Makarov and 9×19mm Parabellum.

However, the high cost of the weapon, complex and time-consuming machining, combined with a limited effective range, large size and weight for a pistol, and fragile buttstock have been mentioned as a reason to phase it out of active service in favour of assault rifles such as the AKS-74U.

Igor Yakovlevich Stechkin, recently graduated in 1948 from the Tula Mechanical Institute, began work on this new automatic weapon concept, competing against other prolific designers such as Vojvodin and Kalashnikov.

Stechkin designed a select-fire pistol capable of accurate fire up to 200 meters, with the possibility of attaching a combination holster/shoulder stock.

A 20,000 round endurance test against an Astra machine pistol and a PPS-43 submachine gun proved that Stechkin's design was promising.

The APS was issued to Soviet Army vehicle operators, artillery crews, and front-line officers and law enforcement, and was used in conflicts in Angola, Libya, Mozambique, Romania, Tanzania and Zambia.

However, the high cost of the weapon, complex and time-consuming machining, combined with a limited effective range, large size and weight for a pistol, fragile buttstock, frequent stoppages and subpar ergonomics, led to the APS being gradually phased out of active service.

The APS shares features with the Makarov service pistol, such as a heel-mounted magazine release, slide-mounted safety lever, and field-strip procedure.

The checkered or serrated grips' panels are made from wood (early models), reddish-brown bakelite or black plastic.

When pointed downwards to the "OD", or single-shot position, the safety lever deactivates the auto-sear and rate reducer to allow semi-automatic fire.

The weight travels down, compressing its spring, then slams back up into the trigger bar, tripping the sear and firing the gun.

The machine pistol may be fitted with a wooden (early), brown bakelite or steel wire shoulder stock (for the APB variant); otherwise, the weapon becomes difficult to control on full auto.

[3] During the Soviet–Afghan War, the APB was used by Soviet Spetsnaz team leaders as an extra weapon; they usually carried on a sling with the suppressor and stock mounted.