Developed in the 1960s, the M79 grenade launcher was one of the first infantry/ hand held explosive firearms, made famous in Vietnam. The China Lake, although similar in appearance, is not the same thing. The China Lake was developed for Navy SEALs, and it is a pump action grenade launcher, while the M79 is a single shot grenade launcher.
In the end of 1940s, United States army had realized the need to fill the gap between 50 m throwing grenade distance and 400 m minimal range of light 60mm mortars. Project NIBLICK had been created to help fill this gap. By 1952, the 40mm projectile was available - a HE charge in a fragmenting metallic shell. Later, by 1953, a shell was developed to change the projectile into ammo. It has to be mentioned, that there were attempts to use rifle cups and spring launchers to launch projectiles, but they were not any notable in performance, apparently.
During the time until 1960, M79s were developed, until in 1961, they went into manufacturing, and were immediately adapted into US Army service, which had the need of weapon of this class to aid war efforts in Vietnam.
Reports of warfare usage had been very good, and despite the fact, that production ended in 1971, M79 are still in use by various armies, and are manufactured on licenses around the globe.
Technically, M79 is simple one-shot breech-load rifle. Barrel is grooved (thus rifle). The M79 is cocked automatically, during the reloading. It breaks down for reloading in vertical direction, barrel tipping forward to open the breech.
Sights are simple iron sights - hooded front, and ladder rear. Rear is marked up by increments of 25 m till 375 m, with accommodations for windage. Stock is fitted with recoil-dampening rubber plate. There is simple manual safety, which also doubles as automatic during the reloading.
Ammo for M79 is built by high-low pressure scheme. Powder load is placed into a high pressure chamber, where it ignites and explodes. Through several vents, gases expand into low pressure chamber, from which it propels the charge. This solution allows for usage of thin barrels, and gives low speeds to projectile, thus making recoil low.
There is a very wide range of ammo available for M79 now - ranging from police-employed tear gas rounds and rubber projectiles to auxiliary loads like flares and smoke grenades, to military explosives, from simple high explosive to incendiary and fragmentation grenades, to close-quarters loads, like buckshot canisters and flechettes.
M79 is very often considered to be the very staple of what "grenade launcher" usually looks like. (While things like RPG-7 are often considered to be rocket launchers, despite having "grenade launcher" straight in the name). Nicknamed "Thumper" and "Blooper" by US troops in Vietnam, it has come to be known as one of the ancestors of modern under barrel grenade launchers such as the M203 and M320 GLM.
- The M79 is affectionately known as the Thumper, Bloop Tube, Blooper or Thump Gun due to its signature report.