The BAR, (Browning Automatic Rifle) was an automatic rifle and / or a light machine gun used by the army of the United Atates of America during the 20th century, today we should call it a Support Automatic Weapon. It was designed by John Browning in 1917. It was distributed in small numbers to the American Expeditionary Force in France and was tested in action. In 1938 it was officially adopted by the American Army as a light machine gun of support for infantry squads, and was still used, albeit in modest quantities, also in the Vietnam War.

The FN Herstal Belgian factory bought the European production rights of the BAR and produced the BAR for the Belgian army, and sold this LMG to Sweden and Poland, until these nations started producing it at home.

Sweden bought the first BARs in 1920 from Colt, before the Belgian Arms Factory FN acquired the European rights for the production of this weapon. Sweden subsequently bought BARs from FN, and then in 1921 began production in Sweden at the Karl Gustav factory. In 1930, the Karl Gustav firm improved the design with a folding carrying handle and with a quick change barrel system.

Poland bought a model of the BAR modified according to the requirements of the Polish army from the Belgian FN, then after some legal disputes it acquired the gun production rights from Colt, and the LMG was produced by the Polish state firm Państwowa Fabryka Karabinów.