Specifications OTs-20 «Gnom» Caliber, mm........................................................................12.3 Cartridge......................................STs110, STs110-04, STs110-02 Overall dimensions, mm.......................................250 x 132 x 45 Empty weight, kg................................................................1.1 Firing mechanism...................................................double action Cylinder capacity, rds.............................................................5

   The GTs-20 Gnom smooth-bore revolver was developed by TsKSB SOO for law-enforcement bodies. though at one time it was marketed as a possible "farmer's weapon". The OTs-20 smoothbore revolver chambered for the STs-100 cartridge was demonstrated in 1996 and represented a totally new approach to side arms, with the main objective being the maximum stopping power of a holster-carried hand arm. The revolver was designed by V.I. Seregsn, A.N. Nevizhin, and S.V. Zotov, while cartridges were developed by the S. M. Sheinin. The OTs-20 was based on the OTs-11 combat revolver and the MTs-RG gas revolver, developed by the same designers.
    A series of 12.5x40 mm cartridges was based on the brass 32-gauge shotgun cartridge case for smoothbore hunting guns. The cartridge case was shortened to 40 mm and fitted with a percussion cap of a pistol round. The baseline STs-110 cartridge is equipped with a pointed steel bullet with a plastic sabot. The sabot with obturating grooves reduces the escape of expanding powder gases between the bullet and the barrel walls and ensures efficient use of their pressure to accelerate the bullet. After the bullet leaves the muzzle, the sabot stabilizes the bullet in the air. The flat-tipped bullet weighs 11 grams. It penetrates a 3 mm steel plate at a range of 50 m0 and a 4.5 mm standard body armor plate at a range of 25 m. Such a bullet is capable of killing a human target-wearing body armor. The STs-110-04 cartridge features a lead bullet, which boasts a weight of 12 g, a muzzle velocity of 350 m/s5 and muzzle energy of 735 joules. While having a significantly lower penetration, the lead bullet transfers its energy to the target faster, thus, ensuring a high slopping power. The STs-110-02 is a lead-shot cartridge containing 16 4.5 mm shots (shot number '00') weighing a total of fen grams, or 5 mm pellets.
    The OTs-20 is a revolver with a swing-out cylinder and an extractor pin. The cylinder is loaded by one round at a time, but spent cases are extracted simultaneously (rimmed cases make simultaneous extraction easy) This generally traditional design is augmented by a number of unique features, in order to align the barrel and the cylinder chamber during a shot, the traditional locking bolt is complemented by a simple device. There are five recesses and five notches on the rear part of the cylinder surface — the Socking bolt snaps into the recesses, while a special trigger rib engages a corresponding notch immediately before a shot is fired, otherwise the revolver will not shoot.
The trigger assembly with a half-hidden hammer is mounted inside a separate case (on the trigger guard) and is dismantled as one piece in stripping. The inertial striker (firing pin) is mounted in the revolver frame. The trigger assembly allows the revolver to conduct single-action and double-action fire. The field-stripped revolver comprises only the following three main parts: the frame with the barrel, the cylinder and the trigger assembly — i. e. the so-called modular design.
    The bore and the cylinder chambers are chrome-plated. The iron sights include a Song foresight on the barrel rib and a rear sight inserted into the frame groove. The revolver reliably hits a half-sihouede target at a range of 25 m. The steel bullet dispersion at a range of 25 m в about 5 cm. The front part! of the frame may fee fitted with a laser target designate Souvenir models of the revolver are equipped with wooden grip plates, while standard versions are fitted with plastic ones. Dimensions of the trigger guard provide for accommodating gloves, while its front edge is designed for two-handed firing.
    The Gnom revolver is quite large and is intended for overt carrying The revolver and spare cartridges are earned in the open belt holster and two pouches with flaps respectively.