The Russian GP-46 40x46mm Grenade Launcher

The Nades

The 40x46 low-velocity grenade round has been used for over half a century. In the 1950s, the United States was developing a weapon system and high-explosive grenades to increase the lethality of infantrymen, something better than rifle grenades. The result was the 40x46 low-velocity grenade and the M79 standalone, single-shot launcher. The development of this program began in 1953, and the M79 was finally adopted in 1960. The grenades achieved a muzzle velocity of approximately 250 feet per second, and their maximum effective range is around 400 meters.

The 40x46mm rounds utilize a high-low propulsion system. Rheinmetall initially developed this high-low pressure concept during World War II. When the round is fired, the primer ignites the propellant in the high-pressure chamber, generating approximately 35,000 pounds per square inch of pressure. This pressure then expands through vent holes into a cup, causing a rapid pressure drop to around 3,000 psi, resulting in over a 90 percent reduction in pressure. This design produces manageable recoil, comparable to a shotgun, and operates at a lower pressure, allowing aluminum barrels to be used.

As the projectile is fired at a speed of 250 feet per second, the rifling inside the barrel imparts a right-hand spin to the grenade at a rate of 37,000 revolutions per minute. This spin, combined with the initial setback upon firing, activates the fuse in the projectile.

Russian Grenade Production

JSP NPO Pribor, a Moscow region-based company, locally produces NATO 40x46mm low-velocity grenades. The Bogorodsk branch of JSC NPO Pribor (Noginsk) is one of Russia's leading manufacturers of small-caliber ammunition and explosives. It also produces electronics, tools, and dies, including the VOG-30D, an extended-range 30mm grenade.

The GP-46 under-barrel grenade launcher can be attached to any AK-based weapon and mounts similarly to other grenade launchers in the GP series. Considering the current situation in Ukraine, utilizing the GP-46 alongside the large quantities of captured Western aid would be wise.

The GP-46

The GP-46 easily mounts, like all other GP series under-barrel grenade launchers. The grenade launcher is attached to the rifle via the accessory lug on the gas block. A rear automatic safety on the GP-46 prevents it from firing when not connected to the rifle or stand-alone unit; unlike traditional GP series grenade launchers, the GP-46 indexes on the receiver to disengage the safety when mounting the launcher to an AK. This safety can be disengaged as a stand-alone shoulder stock is installed. Notably, there is a significant divergence in preferences within the US Army, with my experience where some leaders advocate for weapon-mounted configurations. In contrast, others prefer a stand-alone setup with the M320s.