Probably the longest serving weapon in the U.S. military arsenal is the Browning .50-caliber M2 machine gun. Often referred to as "ma deuce" for its M2 designation, the weapon entered U.S. service at the end of World War I, being scaled up from the Browning .30-caliber M1917 machine gun. The .50-caliber weapon was initially designated M1921.
Using a round designed by Winchester, the .50-caliber machine gun was originally intended for ground troops to use against enemy troops. Subsequently, it was employed as an anti-aircraft weapon and then became the standard armament of U.S. warplanes. In 1932, the design was updated and redesignated M2.
Ground and naval machine guns could be air- or water-cooled, the latter having large "jackets" around the barrel. The weapons had rates of fire from 500 to 650 rounds per minute. Mounts for vehicle and shipboard use soon had twin barrels, while a fixed quad-barrel mount was developed for ground and vehicle use. Its light weight permitted up to eight guns to be carried in fighters and it fit into single-, twin-, and quad-barrel turrets on U.S. bombers. The weapon was used in every theater of World War II by U.S. and allied troops--by 1945 the U.S. Army authorized 237 .50-caliber guns in each infantry division, 385 in each armored division, and 165 in each airborne division.
The "ma duce" was used in large numbers in the Korean and Vietnam Wars, in other crises and conflicts, and, of course, in the Gulf War of 1991 and the later invasions of Afghanistan and Iraq.
Now, after almost 90 years of service, the U.S. Army has moved to replace Browning's remarkable machine gun. The Army recently ordered three prototypes of a lightweight .50-caliber machine gun. Produced by General Dynamics Armament and Technical Products, the weapon weighs about one-half of the current .50-caliber M2HB (Heavy Barrel) machine gun, fires with less recoil and is equipped with technology to improve accuracy, according to the company.
The Army and Special Operations Command (SOCOM) will test the new guns and then apply the lessons learned to a potential production design. Low-rate initial production could begin as soon as 2011.
It would take several years for the new weapon to replace the "ma duce" in U.S. service. But even if it does so, the M1921/M2 would have been in service for a century.
Its inventor -- John Moses Browning (1855-1926) -- was one of America's most prolific gun inventors. After making his first gun from scrap metal at age 13, he went on to design pistols, rifles, and machine guns. The U.S. Army began using his machine guns in 1890. Browning's innovative weapons also included the .30-caliber M1918 Browning Automatic Rifle (BAR), used in U.S. Army and Marine Corps squads from World War I through the Korean War.