| OTs-20 Gnom | |
| Origin: | Russia |
| Type: | Revolver |
| Is Ranged: | yes |
| Service: | MVD[1] |
| Designer: | TsKIB SOO |
| Manufacturer: | KBP Instrument Design Bureau |
| Production Date: | 1994 |
| Number: | 200 |
| Weight: | 1.1 kg (1.17 with ammo) |
| Length: | 250 mm |
| Part Length: | 100 mm (3.93 inches) |
| Width: | 45 mm |
| Height: | 132 mm |
| Cartridge: | 12.5x40mm STs-110 |
| Action: | Double action or single action |
| Velocity: | 350–400 m/s (lethal ammunition) 100 m/s (non-lethal ammunition) |
| Feed: | 5-round cylinder |
| Sights: | Fixed; front blade and rear notch |
The OTs-20 Gnom (ОЦ-20 "Гном")[2] is a Russian revolver manufactured by the KBP Instrument Design Bureau. It uses a proprietary 12.5x40mm STs-110 cartridge developed from a 32 gauge shotgun cartridge. It can fire lead slug (STs-110-04), lead shot (STs-110-02), and armor-piercing steel-core slug (STs-110) cartridges, as well as three types of non-lethal ammunition. The revolver is smooth bore and so it lacks accuracy[3] but has high muzzle velocity and stopping power.
A tactical laser projector is available that mounts on an accessory rail under the ejector rod shroud. It is turned on and off via a pressure switch that can be attached on the grip; the operator just squeezes the grip and the projector goes on or off.
The manufacturer claims that the steel-core slug can penetrate 4.5 mm of "standard body armor plate" at 25 m. They also claim that the dispersion of this bullet at this distance is about 5 cm.
The gun was designed by A.N. Nevizhin (А.Н. Невижин), V.I. Seregin (В.И. Серёгин) and S.V. Zotov (С.В. Зотов) at TsKIB SOO.[4] Its production started in 1994, and only 200 pieces have been known to be made as of 2013. The gun was partially derived from the 9 mm OTs-11 Nickel revolver previously developed by Nevizhin and Zotov.[5]
Before the Gnom, the MVD had already in service a similar item: the KBP 12.3mm UDAR revolver.[3] Derived from the 9mm R-92 revolver, the UDAR was designed to be used as a self-defense and riot-control weapon for undercover or plainclothes police. It uses rounds derived from cut-down 36-gauge shotgun shells and can fire shot, slug or aerosol gas shells.