Grenade launcher

A grenade launcher is a weapon that fires a specially designed, large caliber projectile, often with an explosive, smoke, or gas warhead. Today, the term generally refers to a class of dedicated firearms firing unitary grenade cartridges - for example the widely used 40mm type. The most common type are man-portable, shoulder-fired weapons issued to individuals, although larger crew-served launchers are issued at higher levels of organization by military forces.

Grenade launchers are produced in the form of standalone weapons (either single shot or repeating) or as attachments mounted to a parent firearm, usually a rifle. Larger crew-served automatic grenade launchers such as the Mk 19 are mounted on tripods or vehicles.

Some armored fighting vehicles also mount fixed arrays of short-range, single-shot grenade launchers as a means of defense.

The earliest devices that could be referred to as grenade launchers were slings, which could be used to throw early grenado fuse bombs. The ancestors of modern ballistic grenade launchers, however, were simplistic muzzle-loading devices using a stake-like body to mount a short, large-bore gun barrel into which an explosive or incendiary device could be inserted; these were later refined into shoulder-fired blunderbuss-like firearms referred to as "hand mortars". These weapons were not highly regarded due to their unreliability, requiring the user to ignite a fuse on the projectile before firing, and with a substantial risk of the explosive failing to leave the barrel; attempts to ignite the fuse on firing using the gunpowder charge resulted in weapons that would often force the fuse into the grenade and make it explode in the barrel.

During the First World War, several novel crew-served launchers designed to increase the range of infantry hand grenades were developed, such as the Sauterelle crossbow, the West spring gun, and the Leach trench catapult devices. None were particularly effective, and such devices were ultimately replaced by light mortar systems such as the Stokes mortar, while the task of increasing the range of infantry explosive projectiles was primarily taken by rifle grenades.

A late example of such a system was the Japanese Type 91 grenade, which could be used as a thrown hand grenade, or fitted with adaptors to either be fired as a rifle grenade or used as a projectile by the Type 89 grenade discharger, a light infantry mortar.

A new method of launching grenades was developed during the First World War and used throughout World War II. The principle was to use the soldier's standard rifle as an ersatz mortar, mounting a grenade (in many older cases an infantry hand grenade) fitted with a propelling charge, using an adaptor or socket on the weapon's muzzle or inside a mounted launching cup, and usually firing with the weapon's stock resting on the ground. For older rifle grenades, igniting the charge generally required loading the parent rifle with a special blank propellant cartridge, though modern rifle grenades can be fired using live rounds using "bullet trap" and "shoot through" systems.

The system has some advantages; since it does not have to fit in a weapon's barrel, the warhead can be made larger and more powerful compared to that of a unitary grenade round, and the rifle's weight and handling characteristics are not affected as with underbarrel systems unless a grenade is actually mounted. While older systems required the soldier to carry a separate adaptor or cup to attach to the rifle to make it ready to launch (such as the German Schiessbecher), later rifle grenades were often designed to attach to the standard factory-mounted flash hider of the parent rifle; for example, the NATO-standardized 22 mm rifle grenade can be mounted to most post-WWII Western military rifles without the need for an adaptor.