The GSh-18 pistol, developed by the Tula-based KBP Instrument Design Bureau under the supervision of Designer General A. G. Shipunov and Deputy Designer General V. P. Gryazev, was submitted for official tests in January 2000. The initial Setters of last names of both designers and She magazine capacity serve as the designation of the pistol chambered for the 9x19 cartridge. The designers tried to combine such features as the ability to kill manpower wearing Class 3 body armor (nowadays used almost everywhere to protect military personnel, as well as in certain civilian areas), a large magazine capacity, minimum weight and dimensions, easy carry and firing. The latter feature is represented by its plastic frame and rounded contours. The frame 5s molded from high-strength plastic and reinforced by a metal insert with steel pieces. The GSh-18 entered service with the Ministry of Justice in 2000s while in 2003 it was fielded with the Russian Armed Forces along with the SPS and the PYa pistols The GSh-18 received the index of 6P54.
The pistol is a short-recoil-operated weapon. This operating system allowed the designers to reduce the slide dimensions and weight. The GSh-18 uses a rotating-barrel Socking system. When the barrel rotates by 18°, its ten locking Jugs engage the stopper fixed inside the slide top. The slide top and the slide proper are two separate parts, detached from each other during field stripping. Such design of the slide top allows its manufacturing using forging and welding. Other design features include forced locking of the cartridge extractor to the cartridge case lip when the bore is locked, which improves reliability of the mechanism. The recoil spring with its guide is mounted under the barrel.
The pistol is filled with a striker-type firing mechanism. When the slide recovers (i. e. returns to its forward position), the striker takes a partially cocked position. As a result, all the shooter has to do to cock and fire the striker is to pull the trigger all the way back. Such operation of the firing mechanism is intended to ensure safe carry of the pistol with a chambered round
— if the partially cocked striker accidentally disengages from the sear, the energy of the compressed striker spring, wound aro und the striker, will be insufficient to fire the cap. The rear part of the half-cocked striker protrudes by approximately 1 mm behind the slide and serves as a visual and tactile indicator of the striker's cocking. The automatic trigger safety lever prevents a spontaneous release of the trigger and thus a shot. The trigger safety disengages in the beginning of the trigger travel when the shooter's index finger depresses if into the trigger. The internal automatic safety prevents the pistol from firing with unlocked slide. The pistol has no manual safeties.
The GSh-18 is fed from a detachable double-column magazine. The magazine does not shuffle cartridges onto a single column in its upper portion. An ambidextrous magazine release button can be mounted on either side behind the trigger guard. The pistol is fitted with a slide stop.
The pistol is fitted with a foresight mounted on the slide top and a fixed rear sight on the slide proper. The sights are equipped with bright white inserts (dots) to facilitate aimed low-light fire. The hole in the front part of the trigger guard may be used to mount a laser large! designator.
To reduce the pistol cost and weight, forging, bending, and welding processes are used for manufacturing metal parts and a plastic frame is employed.
Simultaneously with developing the pistol, designers worked on the 9x19 PBP enhanced-penetration cartridge. The 7N31 cartridge with a Sight high-muzzle velocity bullet, which boasts an enhanced penetration and a sufficient stopping power, became a totally new development. The bullet defeats an 8 mm steel plate and penetrates Class 3 body armor at a range of 15-20 m. The GSh-18 can fire other 9x19 cartridges as well.
Generally, the GSh-18 army pistol offers a new combination of small weight and dimensions, maintainability, significant bullet stopping power and penetration, rounded contours, prompt action (no manual safeties) and at the same time sufficient handling safely (automatic safety, cocking the striker when the trigger is pulled).