The M79 is a grenade launcher of US origin. It was designed to provide infantry with explosive firepower between the maximum range of hand grenade and minimum range of light mortar. The M79 was first used during the Vietnam war and proved to be very effective. The M79 has become an iconic firearm and remains the grenade launcher by which others are judged, even though it has become obsolete.

The M79 is a very simple weapon and resembles a sawed off shotgun. The M79 is breech loaded by disengaging the barrel lock after which the barrel will drop down due to gravity and a round can be inserted. As a break open weapon rounds of any length can be inserted. The adjustable leaf sight is mounted on the barrel and can be flipped down when it is not in use.

The M79 is a single shot grenade launcher that fires the 40x46mm low velocity round. Besides the standard high explosive fragmentation rounds there is a wide selection of other rounds available. These include short range flechette and buckshot rounds, marker and smoke rounds and non-lethal rounds such as tear gas. An experienced operator can fire 6 rounds per minute. The M79 proved to be very accurate. Point targets can be engaged out to 150 m and area targets out to 400 m.

The M79 was widely used by US forces during the Vietnam war. It was eventually replacedby the M203, but was issued as a standard issue weapon until the late 1980's. The M79 was also widely exported. Several nations have adopted it as a standard issue weapon, while many others acquired it for use by special units.