GP-25

September 11, 2008

The GP-25 «Koster» underbarrel grenade launcher was adopted (or service in 1978 which was developed at the TsKIB SOO by V. N. Telesh to be employed in the complex with the AKM, AKMS, AK-47 and AKS-74 assault rifles. The Tula-based Ordnance Plant (Armory) had launched the grenade launcher in production.
The GP-25 (Index 6G15) is noted for its simple design and is classed as a muzzle loaded rifled weapon systems.
The VOG-25 or VOG-25P round developed at the GNPP «Pribor» incorporates a grenade and a propellant charge in a case and is being inserted in a barrel without force, thus entering by its 12-lugs of the driving band into the barrel grooves and is being retained in the barrel tube by a spring-actuated latch.

The grenade launcher features the self-cocked firing mechanism of a hammer type with the thumb safety lever that locks the hammer. On the fore grip of the assault rifle is attached the grenade launcher via the brack¬et with a guard and fixed by a latch. In an effort to absorb the recoil effect on the
shooter and the weapon during the fire a rubber-plate is fixed to the stock while a trig¬ger-guard group of the firing mechanism of the GP-25 protects the fore grip of the assault rifle, and the elastic bushing of the frame absorbs the recoil blow against the receiver. The accessories are comprised of the rod of the main spring with the hook which is usually being substituted by the driving rod of the assault rifle designed to prevent the tear off the receiver cover during firing of the grenade launcher.

The iron sight-quadrant is designed for the direct or semi-direct laying and the cor¬rections for derivation of the grenade are being entered automatically. At a range of 400 meters the mean deviations of the grenade account for 6.6 m in range and 3 m on the front.
The GP -25 grenade launcher represent¬ed a rather successful and rather compact complex and easily controlled assault rifle-grenade launcher complex. The direct fire is usually being delivered at ranges of up to 200 meters with a shoulder rest while the fire at a
range of 200-400 meters is delivered with the stock squeezed in the armpit and the fire with a high-angle trajectory is delivered with the stock propped against the ground.

Specifications GP-25
Caliber…………………………40mm
Cartridge………………..VOG-25, VOG-25P
Weapon weight w/o a round ……………1.5 kg
Weapon length …………………..323 mm
Barrel length…………………….205 mm
Muzzle velocity ………………….76 m/sec
Effective rate of fire……………..4-5 rds/min
Max. range of fire…………………..400 m
(flat or high-angle trajectory) Max. range of high-angle trajectory fire……..200 m