The GP series of under-slung, single-shot, muzzle-loading 40mm grenade launchers was developed for the Soviet Army rifleman beginning in 1972. Work spanned into 1978 to which limited production ensued under the KBP Instrument Design Bureau brand label. The type was made compatible with the Kalashnikov "AK" family of assault weapons and intended to broaden the tactical reach of the Soviet infantryman considerably - matching the American M203-armed infantryman per step. The weapon was designed to fire a standard FRAG (FRAGmentation) grenade, smoke, tear gas, anti-riot baton and a specialized "bouncing" grenade and, as such, the GP family of launchers could be called upon to handle a variety of anti-personnel tasks with varying levels of lethality.
The GP was developed around a "High-Low Pressure System" in which to handle the resultant recoil effects of the launching 40mm projectile without the need of a rocket-based propulsion system. The system was devised by German engineers in the latter stages of World War 2 and subsequently adopted by the Soviets in the post-war world. Similarly, the Americans developed their M79 breech-loading 40mm single-shot grenade launcher along the same lines and these saw widespread use in the Vietnam War before being replaced by the underslung 40mm M203 series mated to the M16 assault rifle.
The Soviet single-shot 40mm grenade launcher first appeared in limited form under the designation of "BG-15" to which then the definitive "GP-25" production mark was unveiled. A modernized and simplified form, the "GP-30", has since been introduced which has more-or-less replaced the original aging GP-25 series. The original GP-25 fielded an overall weight of 3.3lbs and overall length of 12.7 inches while the updated GP-30 was made lighter and shorter at 3lbs with a 10.8 inch length. Both shared the same 4.7 inch barrel length and muzzle velocity was equal at 250 feet per second, largely in line with Western offerings. In the GP system, 40mm grenades are actuated by a percussion cap type base which ignites the grenade's propellant, forcing the projectile from the muzzle end of the barrel. The internal makeup of the launcher's barrel is rifled to promote a rotating stabilizing effect on the exiting grenade which allows for greater engagement ranges and some level of accuracy at range when compared to smoothbore barrel types. Construction of the GP family of grenade launchers is noted as very robust, allowing for a prolonged service life in the worst of battlefield conditions - very much a part of Soviet weapons design philosophy.
The GP-25/GP-30 followed conventional design wisdom by making use of the widely-accepted 40mm grenade projectile firing from a single-shot format. Unlike the American M79 and M203 launchers, however, the Soviet/Russian GP-25 / GP-30 was completed as a muzzle-loading weapon (as opposed to the American breech-loading approach). The basic design included a tubular barrel coupled with a short, slab-sided receiver-type assembly which integrated the trigger loop and pistol-type grip containing a thumbhole. The GP series fit under the handguard of AK-style weapon systems with the assault rifle body acting as the host system for the launcher, allowing the infantryman to fire the grenade launcher from the shoulder utilizing a traditional three-point hold.
The GP family of grenade launchers has seen widespread use around the globe, particularly in national armies whose political ties were once (or are still) aligned with the Soviet Union/Russia. Rebel fighters in the Middle East and Southern Asia have been known to favor the type when its availability was made possible. The GP launcher still maintains a presence in the modern Russian Army and has also been issued to forces of Georgia, Lithuania, North Korea, Pakistan, Ukraine and Vietnam. Georgia produces the type under license.
- Area Effect
323 mm (12.72 in)
123 mm (4.84 in)
3.31 lb (1.50 kg)
250 feet-per-second (76 meters-per-second)
1,312 ft (400 m; 437 yd)
BG-15 - Initial Production Designation
GP-25 - Primary Production Version; definitive Cold War mark.
GP-30 - Modernized and lightened variant of the GP-25; reduced production costs; reduced maintenance, handling requirements and overall weight.