page_title: Bren light machine gun
section_title: Development
hierarchical_section_title: Bren light machine gun / Development
caption_attribution_description: English: 1943-01-02. PAPUA, GIROPA POINT. AUSTRALIAN MANNED M3 GENERAL STUART TANKS ATTACKING JAPANESE PILLBOXES IN THE FINAL ASSAULT ON BUNA. MEN OF D COMPANY, 2/12TH BATTALION, FIRE ON 25 JAPANESE (NOT SEEN), USING BREN MK 1 MACHINE GUNS AND SMLE NO 1 MKIII* RIFLES, WHO ARE FLEEING FROM A WRECKED PILLBOX 150 YARDS AWAY. THE PILLBOX WAS DESTROYED BY THE GENERAL STUART TANK SHOWN HERE. IN THE FOREGROUND ARE PRIVATE J. SEARLE AND CORPORAL G. G. FLETCHER. THIS PHOTOGRAPH WAS TAKEN DURING THE ACTUAL FIGHTING. Australian War Memorial, copyright expired, public domain. Image 014001.
context_page_description: The Bren gun is a series of light machine guns made by Britain in the 1930s and used in various roles until 1992. While best known for its role as the British and Commonwealth forces' primary infantry 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. Although fitted with a bipod, it could also be mounted on a tripod or be vehicle-mounted.
  The Bren gun was a licensed version of the Czechoslovak ZGB 33 light machine gun which, in turn, was a modified version of the ZB vz. 26, which British Army officials had tested during a firearms service competition in the 1930s. The later Bren gun featured 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 Small Arms Factory. The designer was Václav Holek, a gun inventor and design engineer.
  In the 1950s, many Bren guns were re-barrelled to accept the 7.62×51mm NATO cartridge and modified to feed from the magazine for the L1 rifle as the L4 light machine gun.
context_section_description: At the close of the First World War in 1918, the British Army was equipped with two main automatic weapons; the Vickers medium machine gun (MMG) and the Lewis light machine gun (LMG). The Vickers was heavy and required a supply of water to keep it in operation, which tended to relegate it to static defence and indirect fire support. The Lewis, although lighter, was still heavy and was prone to frequent stoppages; its barrel could not be changed in the field, which meant that sustained firing resulted in overheating until it stopped altogether. In 1922, to find a replacement for the Lewis, the Small Arms Committee of the British Army ran competitive trials  between the Madsen, the Browning Automatic Rifle (BAR), the Hotchkiss, the Beardmore-Farquhar, and the Lewis itself. Although the BAR was recommended, the sheer number of Lewis guns available and the difficult financial conditions meant that nothing was done. Various new models of light machine gun were tested as they became available, and in 1930, a further set of extensive trials commenced, overseen by Frederick Hubert Vinden. This time the weapons tested included the SIG Neuhausen KE7, the Vickers-Berthier and the Czechoslovak ZB vz.26. The Vickers-Berthier was later adopted by the Indian Army because it could be manufactured at once, rather than wait for the British Lewis production run to finish; it too 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 which had been submitted for the trials. The design was modified to British requirements under new designation ZGB 33, which was then licensed for British manufacture under the Bren name. The major changes were in the magazine and barrel and the lower pistol grip assembly which went from a swivelling grip frame pivoted on the front of the trigger guard to a sliding grip frame which included the forward tripod mount and sliding ejection port cover. The magazine was curved in order to feed the rimmed .303 SAA ("Small Arms Ammunition") cartridge, a change from the various rimless Mauser-design cartridges such as the 8mm 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 ZGB 33, which was licensed for manufacture under the Bren name.
  The Bren was a gas-operated weapon, which 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 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 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. 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. The sights were offset to t
caption: Australian assault on a pillbox at Giropa Point, January 1943
exif: {"Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "GIMP 2.10.14", "Image DateTime": "2020:03:07 14:34:46", "Image ExifOffset": "136", "Thumbnail ImageWidth": "256", "Thumbnail ImageLength": "188", "Thumbnail BitsPerSample": "[8, 8, 8]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail PhotometricInterpretation": "6", "Thumbnail SamplesPerPixel": "3", "Thumbnail JPEGInterchangeFormat": "262", "Thumbnail JPEGInterchangeFormatLength": "12754", "EXIF ColorSpace": "sRGB"}