The M73 and M219 were 7.62 mm NATO caliber machine gun

Machine gun

A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....

s designed for tank use. It was used on the M48 Patton

M48 Patton

The M48 Patton is a medium tank that was designed in the United States. It was the third and final tank to be officially named after General George S. Patton, commander of the U.S. Third Army during World War II and one of the earliest American advocates for the use of tanks in battle It was a...

 and M60 Patton

M60 Patton

The 105 mm Gun Full Tracked Combat Tank, M60, also known unofficially as the M60 Patton, is a first-generation main battle tank introduced in December 1960. It was widely used by the U.S. and its Cold War allies, especially those in NATO, and remains in service throughout the world today...

 MBT series (including the M728 Combat Engineer Vehicle

M728 Combat Engineer Vehicle

The M728 Combat Engineer Vehicle is a military engineering vehicle based on an M60A1 Patton main battle tank chassis with a hydraulically operated dozer blade mounted on the front effectively functioning as an armored bulldozer, plus an A-frame crane boom hinged on either side of the turret and a...

), and on the M551 Sheridan

M551 Sheridan

The M551 Sheridan was a light tank developed by the United States and named after Civil War General Philip Sheridan. It was designed to be landed by parachute and to swim across rivers. It was armed with the technically advanced but troublesome M81/M81E1 152mm gun/launcher which fired conventional...

 Armored Reconnaissance / Airborne Assault Vehicle (AR/AAV).

Design and development

Designed primarily as a coaxial machine gun by the Rock Island Arsenal

Rock Island Arsenal

The Rock Island Arsenal comprises , located on Arsenal Island, originally known as Rock Island, on the Mississippi River between the cities of Davenport, Iowa, and Rock Island, Illinois. It lies within the state of Illinois. The island was originally established as a government site in 1816, with...

 and produced by General Electric

General Electric

General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...

, the M73 was developed as a replacement for the M1919A4E1, M1919A5, and M37 machine guns that continued to serve in the immediate post-WWII environment.

The Machine Gun, 7.62-MM, M73 was officially adopted in 1959. It is an air-cooled, recoil operated machine gun, but also using cartridge gasses to boost recoil. Though designed as a simplified alternative to the M1919 series, was of almost identical weight. The weapon was fitted with a quick-change barrel, pull-chain charging assembly, and could be made to feed from the left or the right hand side (though the left-hand feed was more common).

An attempt to make the M73 useful as a flexible infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

 gun saw the weapon fitted with sights and a pistol grip

Pistol grip

On a firearm or other tool, the pistol grip is that portion of the mechanism that is held by the hand and orients the hand in a forward, vertical orientation, similar to the position one would take with a conventional pistol such as the M1911....

 trigger as the Machine Gun, 7.62-MM, M73C. Equally unpopular, very few of these weapons were produced. Sources claim that it saw limited use in Vietnam.

The M73 suffered from numerous malfunctions and was prone to jamming. An improved M73E1 was eventually developed in 1970 with a simplified ejection system, being type classified as the Machine Gun, 7.62-MM, M73A1. In 1972, it was decided that this weapon was sufficiently different from its predecessor and was redesignated Machine Gun, 7.62-MM, M219. These weapons were eventually replaced by the M60E2 and M240 machine gun, and vehicles still in service using the M73 series were refitted with these weapons.

M73C

• Flexible infantry variant with sights and pistol grip
• Used a special tripod, the XM132

M73A1/M219

• Developed in 1970 as an improved version with simplified ejection mechanism attempting to reduce chronic jamming
• Redesignated in 1972 as the M219

Sources

• Ezell, Ed. Small Arms Today, 2nd Edition. Harrisburg, PA: Stackpole Books, 1988. ISBN 0-8117-2280-5.
• Gervasi, Tom. Arsenal of Democracy III: America's War Machine, the Pursuit of Global Dominance. New York, NY: Grove Press, Inc, 1984. ISBN 0-394-54102-2.