The BAR

  The Browning Automatic Rifle commonly called the BAR was a United States automatic rifle or otherwise called the machine rifle. This is a light machine gun used by the United States and numerous other countries during the 20th century. This weapon is chambered for the .30-06 Springfield rifle cartridge. It was designed by John Browning in 1917 for the U.S. Expeditionary Corps in Europe. It replaced the French-made Chauchat and M1909 Benet-Mercie machine guns.
The BAR was designed to be carried by advancing infantrymen, slung over the shoulder or fired from the hip, such concept of combat is called "walking fire". This technique in combat was necessary for the individual soldier during trench warfare. However in practice, it was most often used as a light machine gun and fired from a bi pod.
Although the weapon did see some action in World War I, the BAR did not become standard issue in the U.S. Army until 1938 when it was issued to squads as a portable light machine gun. It however saw extensive service in both World War II and the Korean War and saw some service early in the Vietnam War. The BAR has since been replaced by the M249 Squad Automatic Weapon as the standard issue light machine gun in the U.S. Army.