The Classic Army M203 Grenade Launcher Short is a rail mounted launcher that will mount on the lower rail of a rail interface system via its integrated quick release mounts. It is used in conjunction with BB shower grenades.Full metal construction, plastic hand guard for comfort.The M203 was the only part of the army's Special Purpose Individual Weapon (SPIW) project to go into production. The M203 has been in service since 1969 and was introduced to U.S. military forces during the early 1970s, replacing the older M79 grenade launcher and the conceptually similar Colt XM148 design. However, while the M79 was a stand-alone weapon (and usually the primary weapon of troops who carried it), the M203 was designed as an under-barrel device attached to an existing rifle. Because the size and weight of 40 mm ammunition limits the quantities that can be carried on patrol, and because a grenade is often not an appropriate weapon for a given engagement (i.e. when the target is at close range or near friendly troops), an under-barrel system has the advantage of allowing its user to also carry a rifle, and to easily switch between the two.A new grenade launcher, the M320, will eventually replace the M203 in the United States Army. The United States Marine Corps, Air Force, Coast Guard, and Navy will continue to use the older M203. The M320 features an advanced day/night sight, a double-action firing mechanism (as opposed to the M203's single-action) as well as other benefits, such as an unobstructed side-loading breech.The M203 grenade launcher is intended to be used as close fire support against point and area targets. The round is designed to be effective at breaking through windows and exploding inside, blowing up doors, producing multiple casualties, destroying bunkers or emplacements, and damaging or disabling soft-skinned vehicles. In the Vietnam war, U.S. Navy and Coast Guard personnel on boats would lob M203 grenades into the water (using the M79 grenade launcher), to preemptively attack Viet Cong swimmers ("sappers") attempting to plant explosives on anchored or moored U.S. water craft.Its primary purpose is to engage enemies in dead space that cannot be reached by direct fire. A well-trained M203 gunner can use his weapon to suppress the enemy, based on movement and sight. In addition, the M203 can be used as a crowd control weapon when equipped with the M651 Tactical CS (tear gas) grenade. Classified as an anti-personnel weapon, the M203 is not intended to be used against armored or heavy vehicles.