The Bren gun

In November 1918, the Lewis Gun remained the principal light-support weapon of the British Army and the unrivalled choice of aircraft observers. Its flaws were well known, but its contribution to the war effort had been immense. Protracted trials seeking a replacement for the Lewis were inconclusive, though a preference was initially expressed for the Browning Automatic Rifle (BAR). Lack of enthusiasm for new weapons and a perceived lack of need continued to restrict progress but, by 1930, work was concentrating on the BAR, a Vickers‑Berthier, a Danish Madsen, a Hungarian Kiralý — all chambered for the rimmed .303 cartridge — and the 7.9mm Czechoslovakian ZB vz. 27. The tests were undertaken with great attention to detail, until a modified ZB vz. 27 known as the ZGB outperformed the Vickers‑Berthier.

Right: The ZB vz. 26 was very successful, and provided the basis for the Bren gun

 

The ZGB originated in a series of guns designed in the early 1920s by Václav Holek (1886-1954) for Zbrojovká Praga. Beginning with the Praga 1, Holek had progressed to the perfected M‑24 Hand‑held Machine Gun, but no sooner had this been adopted by the Czechoslovakian army than the Praga company encountered such severe financial problems that production was switched to state‑owned Zbrojovká Brno. Once minor changes had been made to facilitate mass production, the M‑24 became the ZB vz. 26, supplemented by the vz. 27 and ultimately the vz. 30.

A .303 version of the vz. 27, the ZGB Model 1, arrived in Britain from Brno early in 1931. It soon proved to be good enough to eclipse an improved Vickers‑Berthier and a Darne in the summer of 1931, though the trials suggested a number of improvements.

 

Left: The ZGB 1 (or ZGB vz. 31) was the first of the .303 vz. 26 derivatives

 

 

Holek altered the ZGB Model 1 in 1932 (perhaps in the Enfield workshops) and the short gas tube version performed well enough to convince the British authorities to continue work. The improved ZGB Model 2 of 1932, retaining the gas port close to the breech, had a body and barrel assembly that slid back against a buffer to reduce the recoil sensation. The ZGB Model 3 had a new 30‑round magazine and an attachment for an experimental tele‑lensatic sight under development for the Vickers Gun, and the ZGB Model 4 of 1934 had a shortened barrel. Radial fins and flutes were omitted, as they complicated manufacture out of proportion to any beneficial cooling effects. The position of the back sight was stabilised on the body behind the magazine, and the rate of fire was reduced from 600 to 480 rounds per minute to minimise dispersion.

 

Left: With the ZGB 4, the trials had all but perfected what would become the Bren gun

 

 

The ZGB Improved Model 4 (also known as the Model 4 Type 2), the last gun in the series, had a vertical back sight notch‑plate. Two guns were tested in January 1934, with a handle beneath the butt to allow an underhand grip, and 62 Czech-made Improved Model 4 machine guns, ordered in December 1934, duly appeared in Britain early in 1935.

The finalised ZGB was approved for British service under the acronym Bren (for Brno and Enfield) and a production licence was signed on 24 May 1935. The British authorities sought 84 ‘Guns, Machine, Bren, ·303‑inch Mark I’ from Brno in April 1936 to allow training and familiarisation to begin, and the first of 10,000 guns ordered from the Royal Small Arms Factory at Enfield on 13 November 1936 was test‑fired on 3 September 1937.

Series production began in Enfield in the Spring of 1938, work continuing until May 1939 helped by butts, bipods and carrying handles supplied by BSA Guns Ltd. In March 1938, an order for 7,000 guns for the Canadian Army was given to the John Inglis Company of Toronto, followed in November by 5,000 for Britain. The first Canadian‑made Mk I was test‑fired in March 1940.

 

Left: British Mk I Bren Gun No. BB8559 was made at Enfield early in 1943 (Morphy Auctions)

 

 

To war once more
Enfield held orders for 15,512 Mk I Brens in September 1939, but production was so time-consuming that the last guns from these pre‑war contracts were delivered in 1942.  Consequently, the Bren was only just displacing Lewis Guns from front‑line service when hostilities began.

The loss of vast quantities of equipment on the beaches of Dunkirk reduced the inventory of Bren Guns to merely 2,130, forcing the British, fearful of imminent German invasion, to impress obsolescent Lewis and Hotchkiss guns from store. Production of Bren guns clearly had to be put on a better footing, and attempts were soon being made to simplify the basic design.

Orders placed for Bren guns between 3 September 1939 and 14 March 1944 amounted to 416,658, of which 253,633 came from Enfield by 1945.  Most of the others were made in Canada by Inglis of Toronto, though some were made by the Lithgow manufactory in Australia.

In addition, tens of thousands were made in Britain under the Monotype Scheme. Monotype & May Ltd, the power behind Britain’s leading manufacturer of type‑casting machinery, intended to make Bren guns by combining components made by an engineering syndicate, minimising disruption if individual factories were disabled by air raids.

The principal participants were the Daimler Co. Ltd, the Hercules Cycle Co. Ltd, the Monotype Corporation Ltd, Climax Rock Drill & Engineering Company, Tibbenham & Company, the British Tabulating Machine Co. Ltd and Sigmund Pumps Ltd. Each contractor made specific components which were then assembled in the Monotype factory in Salfords (near the Surrey town of Redhill), where 400 Bren guns were completed weekly. Beginning with 5,000 ordered in January 1940, the Monotype Scheme produced 83,438 guns; the final order, for 10,000, had been placed in March 1944.

Tooling began in the Toronto factory of the John Inglis Company in 1939, but production was still insignificant at the time of Dunkirk. However, Inglis made about 120,000 Bren Guns for Canadian and British forces in 1938–43, and 43,000 7.9mm guns for China in 1943–5.

 

Right: The Inglis Bren Mk II, with the bipod unfolded (Morphy Auctions)

 

 

 

The different types
The pre-war Mark I Bren gun and the Inglis-made ‘C. Mark I’ were about 45.5in long, with 25in barrels, and weighed 22lb 13oz without the 30-round box magazine; cyclic rate averaged about 500rpm. The Mk I was supplemented by the Mark I (Modified) introduced in the autumn of 1940. The new version had the angular Mark I* body, lacked the bracket for the optical sight, and the barrel‑handle base became a simple welded tube. The Mark II butt slide, a simplification of the Mk I, and the new Mark II bipod were fitted. The Mark I Modified Bren was made in Britain only in Enfield, though some subsequently emanated from the Lithgow factory fitted with Australian Mk 3 bipods.

Approved in June 1941 and made exclusively under the Monotype Scheme, the Mark II Bren Gun had a simpler body, a leaf‑pattern back sight, a fixed cocking handle instead of the folding pattern, a simple stamped butt plate, a modified barrel with a detachable flash‑hider/front‑sight assembly, and a single recoil spring instead of two in the butt. The guns were originally made with Mk II bipods, but so many were repaired or altered at a later date that hybrids will be found.  The C. Mark II Bren Gun was similar, but had a distinctive Canadian-made variant of the Mark 3 bipod.

 

Left: The body of the Mk II Inglis Bren, showing the fixed charging handle on the right and the selector on the left side above the trigger (Morphy Auctions)

 

 

 

Too late to see service at Imphal, the Mark 3 Bren gun, approved in May 1944, had a shorter barrel, a lightened body, simpler magazine‑well and ejection port covers, and the plain Mark 4 butt.  Mark I or Mark 3 bipods were standard. Approved concurrently with the Mark 3 to conserve supplies of raw material, the Mark 4 Bren gun had a modified Mark II‑type barrel cradle, noticeably less metal in the body, and an ultra‑short barrel with a new flash‑hider. Changes made after the war ended included the Mark II/1 (1948), and, ultimately, the advent of 7.62×51mm conversions in the L4 series.

Simplified designs
When World War II began, production of the Bren gun was concentrated at Enfield. Though components were being made in Birmingham by BSA, the Royal Small Arms Factory was the only agency assembling and test-firing the light machine-guns.

When the Luftwaffe began to bomb southern England in September 1940, it was clear that one severe raid on Enfield could paralyse or even destroy the only Bren gun assembly‑line operating in Britain. As much of the inventory of light machine guns had been lost at Dunkirk, the situation was potentially very serious.
Efforts had begun in the Spring of 1940 to develop a simple machine gun which could be made by virtually any small engineering workshop. The most Bren‑like of the emergency designs was the Besal, usually credited to Harold Alexander Faulkner (1890-1969) who was listed in 1940 registers as BSA’s chief gun designer. The prototype was demonstrated to the Small Arms Committee in March 1942. It had a skeletal butt and a fixed pistol grip beneath the rear of the body, with the charging handle on the front right side of the breech. The first of several revised versions was submitted in August 1942, cocked by unlatching the pistol grip sub‑assembly and pushing it forward to engage the bolt/piston extension unit, then retracting the components until the striker was held on the sear. This was copied from the Czechoslovakian ZB vz. 53, which had been transformed by BSA into the Besa vehicle gun.

 

Right: The prototype Besal gun

 

 

Testing was successfully undertaken throughout the winter of 1942 on the ranges at Pendine, allowing the Besal to be adopted provisionally as the ‘Gun, Light, Machine, Faulkner, ·303‑inch Mark I’. By the summer of 1943, however, the likelihood of a German invasion of Britain receded and deliveries of Bren Guns from Enfield, Inglis and the Monotype Scheme were meeting demands. Consequently, introduction of the Faulkner machine gun was rescinded on 10 June 1943.

Accessories
The first 17 tripod mounts (copied from the ZB 206) came from Brno in November 1937, destined for trials in India. They were successful enough to persuade the British authorities to place a 3,500‑piece order for ‘Mounts, Tripod, Bren, Mark I’ with BSA Guns Ltd on 3 February 1939; more than 127,000 tripods had been made in Birmingham when World War II ended, though most were destined to spend their lives in store.
There were three differing tripods: the original Mk I, with folding legs and an anti‑aircraft adaptor; the simplified Mk II with fixed legs, introduced about 1941; and the lightweight Mark 2* of 1944, intended for airborne troops.

Among the special anti‑aircraft mounts developed during World War II were the Motley cradle and the Gate, with guns suspended from overhead frames. The Lakeman Mount, a pendant system popular on armoured vehicles in 1940–1, had a large coil spring behind the support arm.

Even though the earliest Bren guns proved to be efficient, their magazines were troublesome.  Consequently, the basic design had soon proceeded from Mk I to the perfected Mk II* by way of Marks I*, I*** and II.
The success of the Bren gun encouraged the British authorities to seek other roles for it. The box magazine clearly limited the ability to sustain fire, a problem which had been recognised as early as 1937 when Vickers‑Armstrong supplied six modified 60‑round Vickers‑Berthier pan magazines for trials.

Two experimental 100‑round drums were acquired from the same source in 1938, but were unsuccessful. Eventually, however, an improved 100-round Mark I magazine was approved to be followed by a Mark II with a folding L‑shape winding handle. Production is said to have approached 950,000, but this may refer to total orders instead of actual output. A 200‑round High Speed Drum was developed for anti‑aircraft use, but is now rarely seen.

 

Left: The Mark I Bren tripod, with onboard traverse control, and the Mk I* magazine box holding twelve 30-round box magazines (Arundel Militaria and Rock Island Auctions)

 

 

 

 

 

Collector’s corner
Immaculate, live-fire Brens with matching parts can sell for as much as $10,000, but legal restrictions mean that there is a greater market in Britain for deactivated examples. Arundel Militaria (www.deactivated-guns.co.uk) is offering an Inglis-made Mk I M for £425, while Real Guns (www.real-gun.com) has a 1942-vintage Inglis Mk I for £885 and a Mk III for £595. Spare barrels can sell for £125-£160 depending on pattern and condition; magazines are usually under £10 though a pristine Mk I, comparatively rare, can fetch £95.

Bren Guns invariably bear maker’s marks on the body, together with proof and inspectors’ marks and cyclical serial numbers in batches of 9,999; when Enfield reached Z9999, work recommenced at AA1. However, some ‘A’ and ‘B’ prefix numbers were used by both Enfield and Lithgow, and continual upgrades ensure that very few guns will now be found with all of their original components.

In addition, many engineering companies were recruited in World War II to help the primary contractors accelerate production. Specific components were often identified with numbers prefixed by ‘M’, ‘N’ and ‘S’, indicating factories in the Midlands, the north or the south of Britain respectively. Enfield had been the sole source of box magazines until additional contractors were recruited in May 1939: the Austin Motor Co. Ltd (code ‘M 13’), BSA Guns Ltd (‘M 47’), the Hercules Cycle Company (‘M 117’), the Monotype Corporation Ltd (‘S 81’) and Wilson & Mathieson (‘N 90’). The roster of manufacturers was subsequently expanded on more than one occasion. Total production was approaching 10,000,000 when the war ended, and 147,500 magazine-filling tools had been made in 1941–2 – nearly half of them by Lines Bros. Ltd.

The 100-round Mark I magazine was made by the Austin Motor Co. Ltd, Lines Bros. Ltd (‘S 68’), the Vickers‑Armstrong factory in Bath (‘S 121’) and Wilson & Mathieson; the Mark II came from E.S.S. (Signs) Ltd (‘S 223’), V. & N. Huntley (‘N 29’), Sigmund Pumps Ltd (‘N 65’) and Waygood Otis Ltd (‘S 292’).

 

 

Left: Veronica ‘Ronnie’ Foster poses in Toronto with a Mk I Bren gun made by her employer, John Inglis & Company (Library & Archives Canada)

 

 

 

 

 

 

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