Bren is a series of light machine guns developed by Britain in the 1930s and used in various roles until 1992. It features a distinctive top-mounted curved box magazine, conical flash hider, and quick change barrel. The name Bren was derived from Brno, the Czechoslovak city in Moravia, where the Zb vz. 26 was designed and Enfield, site of the British Royal Arms Factory. Gas-operated, the Bren used the same .303 ammunition as the standard British bolt-action rifle, the Lee-Enfield, firing at a rate of between 480 and 540 rounds per minute (rpm) depending on the mode.