Bren light machine gun The Bren , usually called the Bren Gun , was a series of light machine gun s adopted by Britain in the 1930s and used in various roles until 1991 . While best known for its role as the British and Commonwealth forces ' primary infantry light machine gun ( LMG ) in World War II , it was also used in the Korean War and saw service throughout the latter half of the 20th century , including the 1982 Falklands War and the 1991 Gulf War . Although fitted with a bipod , it could also be mounted on a tripod or vehicle - mounted . The Bren was a modified version of Czechoslovak - designed light machine guns , the ZB vz . 26 and its descendants , which British Army officials had tested during a firearms service competition in the 1930s . The later Bren featured a distinctive curved box magazine , conical flash hider and quick change barrel . The name Bren was derived from Brno , the Czechoslovak city where the Zb vz . 26 was originally designed ( in Zbrojovka Brno Factory ) , and Enfield , site of the British Royal Small Arms Factory . In the 1950s many Brens were rebarrelled to accept the 7 . 62×51mm NATO cartridge and modified to feed from the magazine for the L1 ( Commonwealth version of the FN FAL ) rifle as the L4 light machine gun . It was replaced in the British Army as the section LMG by the L7 general - purpose machine gun ( GPMG ) , a heavier belt - fed weapon . This was in turn supplemented in the 1980s by the L86 Light Support Weapon firing the 5 . 56×45mm NATO round , leaving the Bren in use only as a pintle mount on some vehicles . The Bren is still sold by Indian Ordnance Factories as the " Gun , Machine 7 . 62mm 1B " . Development . During the early 1900s , the British Army subjected several designs of light machine gun to competitive trials . Among the weapons that were submitted for the trials were the Madsen , Browning Automatic Rifle ( BAR ) , the Neuhausen KE7 and the Vickers - Berthier . The Vickers - Berthier was later adopted by the Indian Army and also saw extensive service in World War II . Following these trials , the British Army adopted the Czechoslovak ZB vz . 26 light machine gun manufactured in Brno in 1935 , although a slightly modified model the ZB vz . 27 rather than the ZB vz . 26 had actually been submitted for the trials . A licence to manufacture was sought , and the Czech design was modified to British requirements . The major changes were in the magazine and barrel . The magazine was curved in order to feed the rimmed . 303 British cartridge , a change from the various rimless Mauser - design cartridges such as the 7 . 92 mm Mauser round previously used by Czech designs . These modifications were categorised in various numbered designations , ZB vz . 27 , ZB vz . 30 , ZB vz . 32 , and finally the ZB vz . 33 , which became the Bren . The Bren was a gas - operated weapon , which used the same . 303 ammunition as the standard British rifle , the Lee - Enfield , firing at a rate of between 480 and 540 rounds per minute ( rpm ) , depending on model . Propellant gases vented from a port towards the muzzle end of the barrel through a regulator ( visible in the photo , just in front of the bipod ) with four quick - adjustment apertures of different sizes , intended to tailor the gas volume to different ambient temperatures ( smallest flow at high temperature , e . g . summer desert , largest at low temperature , e . g . winter Arctic ) . The vented gas drove a piston which in turn actuated the breech block . Each gun came with a spare barrel that could be quickly changed when the barrel became hot during sustained fire , though later guns featured a chrome - lined barrel which reduced the need for a spare . To change barrels , the release catch in front of the magazine was rotated to unlock the barrel . The carrying handle above the barrel was used to grip and remove the hot barrel without risk of burning the hands . The Bren was magazine - fed , which slowed its rate of fire and required more frequent reloading than British belt - fed machine guns such as the larger . 303 Vickers machine gun . However , the slower rate of fire prevented more rapid overheating of the Bren ' s air - cooled barrel , and the Bren was much lighter than belt - fed machine guns which typically had cooling jackets , often liquid filled . The magazines also prevented the ammunition from getting dirty , which was more of a problem with the Vickers with its 250 - round canvas belts . Service . Second World War . In the British and Commonwealth armies , the Bren was generally issued on a scale of one per rifle section , with three rifle sections in each platoon . A further three Bren guns were issued to the Admin platoon of each rifle company . An infantry battalion also had a " carrier " platoon , equipped with Universal Carriers , most of which carried Bren guns . Parachute battalions from 1944 had an extra Bren in the AT platoon . The 66 - man " Assault Troop " of British Commandos had a nominal establishment of four Bren guns . Realising the need for additional section - level firepower , the British Army endeavoured to issue the Bren in great numbers , with a stated goal of one Bren to every four private soldiers . The Bren was operated by a two - man crew , sometimes commanded by a Lance Corporal as an infantry section ' s " gun group " , the remainder of the section forming the " rifle group " . The gunner or " Number 1 " carried and fired the Bren , and a loader or " Number 2 " carried extra magazines , a spare barrel and tool kit . Number 2 helped reload the gun and replace the barrel when it overheated , and spotted targets for Number 1 . Generally , the Bren was fired from the prone position using the attached bipod . On occasion , a Bren gunner would use his weapon on the move supported by a sling , much like an automatic rifle , and from standing or kneeling positions . Using the sling , Australian soldiers regularly fired the Bren from the hip , for instance in the marching fire tactic , a form of suppressive fire moving forward in assault . A Victoria Cross was awarded to Private Bruce Kingsbury for such use at Isurava , New Guinea in 1942 , during the Australians ' fighting retreat from Kokoda . Each British soldier ' s equipment normally included two magazines for his section ' s Bren gun . The large ammunition pouches on the 1937 Pattern Web Equipment were designed around the Bren magazine . Every soldier would be trained to fire the Bren in case of an emergency , though these soldiers did not receive a Bren proficiency badge . The Bren had an effective range of around when fired from a prone position with a bipod . Initial versions of the weapon were sometimes considered too accurate because the cone or pattern of fire was extremely concentrated . Soldiers often expressed a preference for worn - out barrels in order to spread the cone of fire and increase suppressive effects . Later versions of the Bren addressed this issue by providing a wider cone of fire . For a light machine gun of the interwar and early World War II era , the Bren was about average in weight . On long marches in non - operational areas it was often partially disassembled and its parts were carried by two soldiers . The top - mounted magazine vibrated and moved during fire , making the weapon more visible in combat , and many Bren gunners used paint or improvised canvas covers to disguise the prominent magazine . The 30 - round magazine was in practice usually filled with 27 or 28 rounds to prevent jams and avoid wearing out the magazine spring . Care needed to be taken when loading the magazine to ensure that each round went ahead of the previous round , so that the . 303 cartridge rims did not overlap the wrong way , which would cause a jam . In general , the Bren was considered a reliable and effective light machine gun , though in North Africa it was reported to jam regularly unless kept very clean and free of sand or dirt . It was popular with British troops , who respected the Bren for its reliability and combat effectiveness . The quality of the materials used would generally ensure minimal jamming . When the gun did jam through fouling caused by prolonged firing , the operator could adjust the four - position gas regulator to feed more gas to the piston increasing the power to operate the mechanism . The barrel needed to be unlocked and slid forward slightly to allow the regulator to be turned . It was even said that all problems with the Bren could simply be cleared by hitting the gun , turning the regulator , or doing both . A complicated tripod mount was available to allow the Bren to be used as an indirect - fire weapon , but this was rarely used in the field . The Bren was also used on many vehicles , including on Universal Carrier s , to which it gave the alternative name " Bren Gun Carrier " , and on tanks and armoured cars . However , it could not be used as a co - axial weapon on tanks , as the magazine restricted its depression and was awkward to handle in confined spaces , and it was therefore used on a pintle mount only . ( The belt fed Vickers or BESA , the latter being another Czechoslovak machine gun design adopted by the British , were instead used as co - axial weapons . ) The Bren was also employed in the anti - aircraft role . A tall tripod was available to allow high angle fire . There were also several designs of less portable mountings , including the " Gallows " and " Motley " mounts . A 100 - round pan magazine was available for the Bren for use in the anti - aircraft role . The Bren ' s direct ancestor , the Czechoslovak ZB vz . 26 , was also used in World War 2 by German and Romanian forces , including units of the Waffen SS . Many 7 . 92 mm ZB light machine guns were shipped to China , where they were employed first against the Japanese in World War II , and later against UN forces in Korea , including British and Commonwealth units . Some ex - Chinese Czech ZB weapons were also in use in the early stages of the Vietnam War . Production of a 7 . 92 mm round model for the Far East was carried out by Inglis of Canada . Post - war . The Bren was used by the British Army , and the armies of various countries of the Commonwealth , in the Korean War , the Malayan Emergency , the Mau Mau Uprising and the Indonesia – Malaysia confrontation , where it was preferred to its replacement , the belt - fed GPMG , on account of its lighter weight . During the Falklands War in 1982 , 40 Commando Royal Marines carried one LMG and one GPMG per section . When the British Army adopted the 7 . 62 mm NATO cartridge , the Bren was re - designed to 7 . 62 mm calibre , fitted with a new bolt , barrel and magazine . It was redesignated as the L4 Light Machine Gun ( in various sub - versions ) and remained in British Army service into the 1990s . The conical flash hider was replaced by the slotted type similar to that of the contemporary L1 rifle and L7 General Purpose Machine Gun . The change from a rimmed to rimless cartridge and nearly straight magazine improved feeding considerably , and allowed use of 20 - round magazines from the 7 . 62 mm L1A1 Self - Loading Rifle . The 30 - round magazine from the L4 also fitted the L1A1 rifle , but the magazine spring was not always strong enough to provide enough upward pressure to feed rounds correctly , this however was fixed by stretching the magazine springs . Completion of the move to a 5 . 56 mm NATO cartridge led to the Bren / L4 being removed from the list of approved weapons and then withdrawn from service . The fact that Bren guns remained in service for so many years with so many different countries in so many wars says much about the quality of the basic design . The Mark III Bren remained in limited use with the Army Reserve of the Irish Defence Forces until 2006 , when it was replaced by the 7 . 62 mm FN MAG ( GPMG ) . The weapon was popular with the soldiers who fired it ( known as Brenners ) as it was light and durable , and had a reputation for accuracy . The most notable use of the Bren by Irish forces was in the Congo Crisis during the 1960s , when the Bren was the regular army ' s standard section automatic weapon . Variants . Mark 1 . From September 1937 . The original Bren based on the Czechoslovak gun . Features : Mark 2 . Introduced 1941 . A simpler version of the Mk 1 . Produced by Inglis of Canada and the Monotype Group through a number of component manufacturing factories . Sometimes known as the " Garage hands " model . Features : The Bren Mk2 was much simplified in the body , which although still being milled from a solid billet of steel , required significantly fewer milling operations than the Mk1 which gives it a much cleaner appearance . The bipod was simplified in design as well as not having extending legs . Most Mk2 bipods resemble a simple ' A ' frame and were more ' soldier proof ' . The Mk2 also featured a slightly higher rate of fire than the Mk1 . The woodwork on the Mk2 was simplified by being less ornate and ergonomic , which sped up the manufacturing process . The barrel was also simplified by means of a non - stepped removable flash hider and in some cases , a barrel fore - end that was matte instead of highly polished . The buffered buttplate of the Mk1 was omitted and replaced with a sheet metal buttplate . Mark 3 . A shorter and lighter Bren made by Enfield from 1944 for the war in the East and for Airborne Forces . This was a conversion of the Mk1 whose main distinguishing feature was a shorter barrel . Mark 4 . As with the Mk3 but this was a conversion of a Mk2 . L4 . A conversion of the Bren to 7 . 62mm NATO from 1958 . Indian Army variants may be new - build , not conversions . L4 Brens can easily be identified by their different magazine . The British issue L4 magazine is of 30 - round capacity and has a slight curve . The L4 magazine was interchangeable with the L1A1 SLR magazine , so the L4 Bren also can be seen fitted with straight 20 - round magazines from the SLR or with the straight 30 - round magazine from the Australian L2A1 or Canadian C2A1 heavy - barrel SLR . The flash suppressor was changed from the cone type of . 303 variants to a slotted type similar in appearance to that used on the SLR and L7 GPMG . All L4s are chambered for 7 . 62×51mm NATO rimless ammunition . Taden gun . The Taden gun was a development of the Bren to use with the . 280 British intermediate round proposed to replace the . 303 in British service . The Taden was belt - fed with spade grips and would have replaced both the Bren and the Vickers machine gun . Although reliable it was not accepted due to the US - driven standardization within NATO on the larger 7 . 62x51mm NATO round . Semiautomatic Bren guns . Many nations ' militaries have disposed of their Bren guns as surplus to their needs . Surplus Brens have been imported to the United States for sale to collectors , but due to US gun laws restricting the importation of automatic weapons such guns must be legally destroyed by cutting up the receivers . A number of US gunsmiths have manufactured new semiautomatic Brens by welding the pieces of destroyed receivers back together , with modifications to prevent the use of full automatic parts , and fitting new fire control components capable of only semiautomatic fire . The balance of the parts are surplus Bren parts . Such " semiautomatic machineguns " are legally considered rifles under US Federal law and the laws of most states . Twin barrel variant . A twin barrel variant of the Bren was manufactured in China during the 1950s from ZB26 light machine guns . It came with side by side barrels and was chambered in the 7 . 62x39mm round fed from AK47 magazines . The only known example can be seen at the Tongzhou militia museum .