The Browning M1919 was a .30 caliber machine gun with a variety of variants, extensively utilized during the 20th century.
The machine gun was used as a coaxial, light infantry, aircraft, mounted, and anti-aircraft machine gun by the United States and numerous other countries, specifically during the Korean War, World War II, and the Vietnam War. Though the weapon began to be usurped by newer more efficient disngs in teh later half of the century, for example the M60 machine gun, the Browning M1919 remained in use in may NATO allied countries and elswewhere throughout the world for much longer.
Various M1919s were rechambered for the new 7.62 x 51 NATO round and served well throughout the 1990's, as well as up through the present day in other countries. The US Navy frequently converted many to 7.62 NATO, and referred to them as MK21 Mod0, the Browning M1919 was commonly used on river craft in throughout the Vietnam era in the 1960's and 1970's.