|Place of origin||Russia|
|Used by||Russian Interior Ministry|
|Length||615 mm (24.2 in)|
368 mm (14.5 in)
|Barrel length||129 millimetres (5.1 in)|
|Cartridge||40 mm caseless grenades: VOG-25, VOG-25P, GRD-40 and "Gvozd" (Nail)|
|Rate of fire||5–6 rpm aimed shots|
20 rpm area suppression
|Muzzle velocity||76.5 m/s (251 ft/s)|
|Effective firing range||250 meters|
|Feed system||Single shot|
|Sights||Flip-up tangent sights|
The RGM-40 Kastet (English: Brass knuckles) grenade launcher is a stand-alone version of the Russian GP-30 grenade launcher with a telescoping stock, AK-type pistol-grip and flip-up tangent sights. It is a single-shot muzzle loaded weapon with a self-cocking trigger mechanism and offers a high degree of commonality with the GP-30. It was designed primarily for police use and can use a wide range non-lethal ammunition (e.g. tear gas, stun grenades, etc.). It can also use standard 40mm VOG-25 and VOG-25P fragmentation grenades.
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- "RGM "Kastet" grenade launcher". Retrieved 23 November 2014.
- "Гранатомет РГМ-40 "Кастет" - Военный портал". Retrieved 23 November 2014.
- "Russian security forces ordered five times more RGS-50M grenade launchers compared to 2014 11112151 | weapons defence industry military technology UK | analysis focus army defence military industry army".
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