History
Designed by Igor Stechkin, the Stechkin APS was put into service in 1951 alongside the Makarov, both pistols replacing the venerable TT-33. The Stechkin APS was meant to be used as a sidearm for artillery soldiers, tank crew, pilots, and other people who worked in or around vehicles and needed a small but powerful weapon. It was replaced by the AKS-74U in this role.
Chamberings
The Stechkin APS was originally chambered in 7.62x25mm Tokarev, but now is commonly found in 9x19mm Parabellum and 9x18 Makarov chamberings.