M79 grenade launcher

Launcher, Grenade, 40 mm, M79
M79 with the leaf-type sight unfolded.
Type	Grenade launcher
Place of origin	United States
Service history
In service	1961–present
Used by	See Users
Wars	Vietnam War Cambodian Civil War Falklands War Bougainville Civil War Afghan War Iraq War Cambodian–Thai border dispute 2010 Burma border clashes Syrian Civil War
Production history
Designer	Springfield Armory
Designed	1953–1960
Manufacturer	Springfield Armory, Action Manufacturing Company, Exotic Metal Products, Kanarr Corporation, and Thompson-Ramo-Wooldridge
Produced	1961–1971
Number built	350,000 (U.S. only)
Specifications
Weight	2.93 kg (6.45 lb) loaded 2.7 kg (5.95 lb) empty
Length	73.1 cm (28.78 in)
Barrel length	35.7 cm (14 in)
Cartridge	40×46mm grenade
Action	Break-action
Rate of fire	6 rounds/min
Muzzle velocity	76 m/s (247 ft/s)
Effective firing range	350 m (383 yd)
Maximum firing range	400 m (437 yd)
Feed system	breech-loaded
Sights	Blade and leaf type

The M79 grenade launcher is a single-shot, shoulder-fired, break-action grenade launcher that fires a 40×46mm grenade, which uses what the US Army calls the High-Low Propulsion System to keep recoil forces low, and first appeared during the Vietnam War. Because of its distinctive report, it has earned the nicknames of "Thumper", "Thump-Gun", "Bloop Tube", and "Blooper" among American soldiers as well as "Can Cannon" in reference to the grenade size; Australian units referred to it as the "Wombat Gun". The M79 can fire a wide variety of 40 mm rounds, including explosive, anti-personnel, smoke, buckshot, flechette (pointed steel projectiles with a vaned tail for stable flight), and illumination. While largely replaced by the M203, the M79 has remained in service in many units worldwide in niche roles.

The M79 was a result of Project Niblick, an attempt to increase firepower for the infantryman by having an explosive projectile more accurate with further range than rifle grenades, but more portable than a mortar. Project Niblick created the 40 x 46 mm grenade, but was unable to create a satisfactory launcher for it that could fire more than a single shot. One of the launchers at Springfield Armory was the three-shot "harmonica" T148 (not to be confused with the later, underbarrel XM148), which did see some limited production and fielding in Vietnam, but problems with the three-round magazine prevented widespread acceptance. The other design was a single-shot break-open, shoulder-fired weapon, the S-3. This was refined into the S-5, which resembled an oversized single-barrel shotgun. Unable to solve the problems with the multi-shot T148 launcher, the Army adopted the S-5 as the XM79. With a new sight, the XM79 was officially adopted as the M79 on December 15, 1960.