The GP-25 is an underbarrel, muzzleloading grenade launcher which is usually fitted onto weapons of the AK series. It fires 40mm caseless grenade cartridges at a muzzle velocity of 76.5 meters per second.
It was first produced in 1978. Its notched quadrant sights are adjustable up to 400 meters. It fires the VOG-25 fragmentation grenades, with a lethality range of 6 meters; the VOG-25P bouncing grenades, which bounce 0.5-1.5 meters off the ground before being detonated by an impact delay fuse and also has a lethality range of 6 meters; the GRD-50, GRD-100, and GRD-200 smoke grenades, for use at 50, 100, and 200 meters respectively and capable of producing a 20 square meter cloud of smoke that lasts for one minute in winds up to five meters per second; the Gvozd CS gas grenade; and a baton grenade.
Although normally described as caseless, the grenade does have a cartridge casing, but it is fired along with the main round.