The SPS (Russian: СПС, Самозарядный пистолет Сердюкова, meaning "Serdyukov Self-loading Pistol") is a Russian pistol. Its GRAU index code is 6P53.
It is also known as the Gyurza (Russian: Гюрза; English: Blunt-nosed viper) and SR-1 Vektor (Russian: СР-1 Вектор) during development.
The SPS was designed within the army program "Grach" to develop weapons for enhanced 9×21mm Gyurza ammunition. It was rejected by the army, but was immediately picked up by law enforcement agencies like FSB, as a replacement for the APS pistols.
In the late 1990s, however, the SPS was again picked up by the army, and was modified - the handle was redesigned for better ergonomics. Supposedly, it is currently used by the FSB, FSO and the Spetsnaz.
Technically, SPS is recoil-operated, double-action pistol. It has two safety buttons. One is placed on the back of handle, and is switched off, when pistol is properly held in hand. Other is on the trigger, and is switched off priorly to shot, during trigger pull.
SPS uses powerful 9×21mm Gyurza ammunition, particularly of the 7N29 load, which is capable of defeating Class 3 bulletproof vests (30 layers of kevlar + 2.8 mm titanium plating) at 50 meters.
Current production version. Modified version with ergonomic improvements and minor internal differences.
Modification kit for SR1M, with optional picatinny rails and a quick-detach suppressor, designed to work with supersonic 9×21 ammunition.