SPS was designed within the army program "Grach" to develop weapons for enhanced 9x21 mm ammunition. It was rejected by army, but immediately picked up by law-enforcement agencies like FSB, as a replacement for APS pistols. In the late 1990s, however, SPS was again picked up by army, and was modified - handle was redesigned for better ergonomy. Supposedly, it is currently used by FSB, FSO and SpetsNaz. SPS uses powerful 9x21 mm ammunition, capable of defeating class 3 bulletproof vest (30 layers of kevlar + 2.8 mm titan plate) at 50 meters.