The Browning Automatic Rifle (or BAR) is an American-made gas operated open bolt select fire light machine gun. It was originally chambered in .30-06 but has since been adapted to many other calibers. It features a removable box magazine that holds 20 rounds. The BAR was used in WWII, Korea, and Vietnam before being replaced by more modern weapons.
The BAR was developed during the First World War as an alternative to heavier machine guns, with an emphasis on greater mobility. Its design allowed for the "walking fire" method of engagement, inspired in part by the Chauchat light machine gun used by the French.