During the year of these weekly weapons features, the small arms designers of Czechoslovakia have time and again risen to the top as innovators in the field. And this week, the Bren Gun will be profiled, but this British weapon has its roots in Eastern Europe.
Like the FN MAG, the Bren gun is an automatic weapon considered one of the best in the small arms world. It also gave its name to a small tracked armored vehicle and, in Canada, that country's version of Rosie the Riveter would be popularized because of the Bren.
The Bren light machine gun entered service on the eve of World War II and remained in the service of Great Britain until the early 1990s. It came into British service during a light machine gun competition held during the early 1930s. From Czechoslovakia designers arrived with the ZB vz 26, a magazine fed, quick change barrel light machine gun. That same gun, with some modifications, would become the Bren light machine gun.
The Czech machine gun was in 7.92 x 57mm Mauser, where the British version would be chambered in .303 (or 7.7mm.) And in it's second life, post-World War II Bren guns in British armories would be re-chambered for the NATO standard 7.62 x 51mm round, giving it a longevity into the early 1990s.
As with most weapons, especially in the case of Commonwealth designs, you might be wondering where the name Bren came from. Well it was a hybrid of Brno, the location in Czechoslovakia where the machine gun was first developed and Enfield Lock to become BREN.
With a rate of fire of 500 rounds per minute, it provided an accurate and consistent stream of bullets downrange. However, should you be immersed in heavy action, inevitably the barrel would heat up. And unlike the BAR, it's American counterpart, the Bren had the advantage of a truly quick change barrel. The barrel could be removed by disengaging a latch on the left side of the gun at the point where the barrel meets the receiver. Withdrawing the barrel forward removed it, to be replaced just as quickly by a spare barrel, taking mere seconds to achieve.
The rimmed .303 ammunition of the British also prompted a change in the magazine. To accommodate the rimmed ammunition case, the Bren magazine was curved to improve reliability. At 30 rounds, the Bren gun had the right mix of capacity and portability for the battlefield.
That 30 round magazine, known for its sturdy construction, fed into the Bren receiver from the top. Where most weapons feed from a magazine inserted from the bottom up, the Bren did it in reverse. This meant that expended rounds were ejected downwards, rather than to the side.
Since the Bren was fed from a ventrally mounted magazine, sights for the light machine gun were off-set to the right of the barrel. Angled slightly from rear to front meant while out of line with the barrel, rounds would still impact where aimed.
The gas operated Bren siphoned off propellant gases near the muzzle, pushing on a piston mounted below the barrel. The rear of the piston assembly engaged a notch in the Bren's breach block. As the piston moved rearwards it drew the block backwards against the pressure of a buffer spring. At the same time, the firing pin and hammer retracted as well, ejecting the spent case down and out of the gun. Upon the return stroke, the Bren's bolt stripped a fresh round from the magazine, the piston moved forward and bolt closed.
The simplicity of the Bren was apparent and once adopted by the British military it would see an initial production run of 30,000 machine guns by 1940.
It was that production, especially after the start of World War II that would give rise to the Canadian version of America's Rose the Riveter, "Ronnie the Bren Gun Girl;" and the Bren would find a home inside a special tracked vehicle, along with service in numerous countries into the late 20th century- all covered in Part II.