The end of the First World War, heralded as the advent of the Great Peace, presented most armed forces with paradoxical arguments. The reduction of the army establishment to a fraction of its wartime strength led to the scrapping of thousands of guns; on the other hand, however, the emergence of new types of firearm could not be ignored. Among the most important new infantry small arms were the 'machine pistol' (submachine-gun) and the light machine-gun, and most military agencies were well aware that development work was needed to keep abreast of their rivals.
Trials were undertaken in Britain in December 1922 with a bipod-mounted Browning Automatic Rifle, a Danish Madsen, a Beardmore-Farquhar, a Hotchkiss and a lightened Lewis Gun. Apart from the Beardmore-Farquhar and Lewis, both of which had pan magazines, the guns all fed from detachable boxes on top of the receiver. Reports submitted by the 13th Hussars and the Dorset Regiment suggested that none of the guns was good enough to replace the Lewis Gun in British service, though the Browning Automatic Rifle performed well enough to persuade the Small Arms Committee to recommend it for standardisation. Procurement of the 'Browning Light Machine Gun' fell foul of the Treasury and the project proceeded no farther than some prototypes.
The Bearmore- Farquhar performed well enough in trials undertaken in 1919 by the R.A.F., encouraging the promoters to enter a modified version in the Army light machine-gun trials. An unusual combination of gas and spring action allowed the weapon to be slightly built by the standards of its day, weighing merely 16½lb with a 77-round pan magazine. This was appreciably less than the Lewis Gun, but the Small Arms Committee worried about the exposure of the operating mechanism to the elements.
Owing to lack of enthusiasm for new weapons, and a perceived lack of need, the trials meandered through the 1920s. Improved Beardmore-Farquhars were tested against French Mle. 24 (Châtellerault) and Swiss Fürrer designs. A .303 Browning Automatic Rifle proved inferior to the original .30-calibre pattern and was swiftly abandoned.
By 1930, work was concentrating on the Browning Automatic Rifle, a Vickers-Berthier, a Danish Madsen, a Hungarian Kiralyall chambered for the rimmed .303 cartridgeand the 7.9mm Czechosolvakian Z.B. vz. 27. The tests were undertaken with a commendable attention to detail, including accuracy, endurance and handling characteristics. The Z.B. vz. 27 was eventually preferred to the Vickers-Berthier, though differences in chambering (7.9mm and .303 respectively) hindered direct comparison.
The Z.G.B. had originated in a series of guns designed in the early 1920s by Vaclav Holek for Zbrojovka Praga. Beginning with the Praga 1, Holek had progressed by way of the Praga 2a and 1-23 to the perfected M-24 'Hand-held Machine Gun'. No sooner had this been adopted by the Czechoslovakian army, however, than the Praga company encountered such severe financial problems that production was switched to the state-owned Zbrojovka Brno.
had made some minor changes to facilitate mass production, the M-24 became the
Z.B. vz. 26. Series production began immediately in Brno for the armed forces,
but improvements in the bolt and gas system soon led to the vz. 27. The principal
difference concerned the method of unlocking the bolt, which was achieved by
cam tracks on the outside surface of the piston-rod extension (vz. 26), acting
on the front of the breech-block, or by a cam surface on the piston post (vz.
27) acting towards the rear of the breechblock. The vz. 27 was not standardised
by the Czechoslovakian army, where it was superseded by the vz. 30. This had
an additional safety lug on the barrel lock-nut collar, a stronger piston and
a better gas-regulation system. Czechoslovakian machine-guns were very popular
prior to the Second World War, selling in large numbers. Production licences
were granted to Romania and Yugoslavia, whilst Brno-made examples went to (among
others) Bulgaria, China, Portugal and Turkey.
The Z.G.B. patterns
Cartridge-compatibility problems with the Z.B. vz. 27 were overcome by ordering a .303 version, the prototype Z.G.B. Model 1 arriving in Britain from Brno early in 1931. It soon proved to be good enough to see off an improved Vickers-Berthier and a .303 Darne in the summer of 1931, though excessive fouling accumulated at the gas port and the action had too little power to extract and eject satisfactorily in adverse conditions. Holek altered the Z.B. vz. 30 Model 1 in 1932 (perhaps in the Enfield workshops) and the short-tube version performed well enough to convince the British to continue work.
The improved Z.G.B. Model 2 of 1932 also had its gas port closer to the breech, but the body and barrel assembly were allowed to slide back against a buffer to reduce the recoil sensation. The Z.G.B. Model 3 (also dating from 1933) had a new thirty-round magazine and an attachment for an experimental 'Tele-Lensatic' sight under development for the Vickers Gun. Virtually a prototype of the perfected Bren Gun, the Z.G.B. Model 4 of 1934 had a shorter barrel than the preceding guns. The fins radiating from the barrel were abandoned, as they complicated manufacture out of all proportion to their beneficial effect on cooling; it was far easier to provide exchangeable barrels. The back sight of the Z.G.B. Model 4 lay on the receiver behind the magazine, and the rate of fire was reduced from 600 rpm to 480 rpm to reduce dispersion. The Z.G.B. 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 examples were tested in January 1934, identifiable by the auxiliary handle beneath the butt to allow an underhand grip.
Above: though marked 'Z.G.B. 33', this is the experimental Z.G.B. Model 4, virtually a Bren Gun in all but detail.
A total of 62 Improved Model 4 machine-guns, ordered from Czechoslovakia in December 1934, appeared in Britain early in 1935. The success of the trials, the finalised Z.G.B. was approved for British service under the acronym 'Bren' (for Brno and Enfield) and a production licence was signed on 24th May 1935.
The rival designs
The Vickers-Berthier light machine-gun was favoured to win the British Army trials prior to the submission of the Z.B. vz. 27. Patented prior to the First World War by the Frenchman Adolphe Berthier, the gas-operated Berthier was offered as a light machine-gun or a heavy automatic rifle. The locking mechanism relied on a tilting bolt.
The U.S. Army had been sufficiently impressed by the weapon to provisionally adopt the light machine-gun for military service, but the First World War ended before series production could begin. Tests undertaken more leisurely in 1919-20 period, with Berthiers made by the U.S. Machine Gun Company, were much less encouraging, suggested that first impressions were misleading. The success of the Browning Automatic Rifle and prejudice in the U.S. Army against top-mounted box magazines were two major factors in the ultimate failure of the Berthier in the U.S.A. However, rights to the Berthier patents had been acquired in 1918 by Vickers. Development of a .303-calibre version, begun in 1925, had led to an investment of more than £100,000 by 1931. The Vickers-Berthier ('V.B.') ground gun and its aircraft version, the Vickers Gas Operated ('V.G.O.'), had both been perfected by the late 1920s.
V.B. machine-guns took part in the British trials of 19301, but were soon eclipsed-perhaps unexpectedly-by the Czechoslovakian Z.B. However, though the metric-standard Z.B. was preferred by the army, development of the finalised imperial-standard weapon for series production in the Royal Small Arms Factory would clearly be protracted. As the situation in the Indian Army had become intolerable, owing to the unreliability of its obsolescent Hotchkiss and Lewis guns, the Vickers-Berthier was adopted in 1935.
The 'Gun, Machine, Vickers-Berthier, .303-inch, Indian Mark l' resembled the Bren externally, but had a distinctive pistol-grip assembly. Three hundred were supplied from the Vickers factory in Crayford, Kent, in March 1936; 64 guns had gone to Iraq in 1935, but no other sizeable export orders are known. The 'I. Mark II' Vickers-Berthier was an experimental gun distinguished by a slender butt, an unusually light barrel, and panels milled out of the receiver. Though it weighed 3lb less than the I. Mk I pattern, the Mk II was never adopted by the Indian authorities. The .303 Vickers-Berthiers I. Mark III and I. Mark IIIB, differing largely in barrel design and gas-plug arrangements, were derived from the Mk I and made in the Ishapur rifle factory from 1939 until work stopped early in 1942 so that tooling for the Bren Gun could begin. The I. Mk IIIB was 46½in long, had a 24in barrel, five-groove rifling twisting to the right, and weighed 21lb without it: thirty-round magazine. Its cyclic rate is believed to have been about 450 rpm.
The first Bren Guns
Though 84 'Guns, Machine, Bren, .303-inch Mark l' were sought from Brno in April 1936, the first of ten thousand ordered from the Royal Small Arms Factory at Enfield on 13th November 1936 was completed in September 1937. The order was completed in May 1939 with the assistance of B.S.A. Guns Ltd (which supplied the butts, bipods and carrying handles). The first British-made Bren Gun was test-fired on 3rd September 1937 and series production began in Enfield in the Spring of 1938. In October 1938, a supplementary order for five thousand was given to the John Inglis Company of Toronto, the first Canadian-made Mk I being test-fired in March 1940.
The first seventeen tripod mounts (copied from the Z.B. 206) came from Brno in November 1937, destined for India. They were successful enough to persuade the British authorities to place a 3,500-piece order for 'Mounts, Tripod, Bren, Mark I' with B.S.A. Guns Ltd in 3rd February 1939; more than 127,000 Mk I and Mk II tripods had been made in Birmingham when the Second World War ended, though most were destined to spend their lives in store.
The Second World War
When the war began in September 1939, Enfield had received orders for 15,512 Mk I Brens. Production was so slow and deliberate that the last guns from these pre-war contracts were delivered only in 1942. Consequently, the Bren was only just displacing Lewis Guns from front-line service when war hostilities began. The loss of vast quantities of equipment on the beaches of Dunkirk soon reduced the inventory of Bren Guns to just 2130, forcing the British, fearful of imminent German invasion, to impress obsolescent Lewis and Hotchkiss guns from store. Production of Bren Guns was put on a better footing, and attempts were made to simplify the basic design.
Orders placed for Bren Guns between 3rd September 1939 and 14th March 1944 amounted to 416,658, roughly 220,000 emanating from the Enfield factory in 19406. Most of the others were made in Canada by Inglis of Toronto, or 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 any of the 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 made only a few individual components, which were then assembled into Bren Guns in the Monotype factory in Salfords (near the Surrey town of Redhill) where four hundred were completed weekly. Construction of an additional proof-firing range near the Climax factory in Carn Brea was authorised in October 1940. Beginning with five thousand Brens ordered in January 1940, the Monotype Scheme produced 83,438 guns; the final ten thousand were ordered in March 1944.
Many other engineering companies were gradually recruited to accelerate production. The origin of these parts are often identifiable by numerical codes, prefixed by letters 'M', 'N' and'S' indicating that the factories were in the Midlands, the north or the south of Britain respectively. Participants ranged from the Austin Motor Company Ltd ('M 13'), which made box magazines and magazine components in its Longbridge Works, to Wilson & Mathieson Ltd of Leeds ('N 90'), a maker of parts for the 100-round drum magazine.
Tooling had begun
in the Toronto factory of the John Inglis Company in 1939, but production was
still insignificant by the period of the Dunkirk evacuation. However, Inglis
subsequently made Bren Guns for Canadian and British forces, about 120,000 .303
guns in 193843, and also for China (about 43,000 7.9mm guns in 19435).
A handful of experimental .3006 guns were also made.
When the Luftwaffe began to bomb southern England in the autumn of 1940, it was clear that one severe raid on Enfield could paralyse or perhaps 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.
Though one solution had already been offered in the Monotype Scheme, efforts began as early as the autumn of 1940 to develop a simple machine-gun which could be made by virtually any small engineering workshop. Very little information survives concerning the Garage Gun, alias D.D./E./2285, and the Hefah V (a simplified Lewis touted by the Ductile Steel Co. of Wednesfield) never entered production, even though it was adopted by the navy early in 1942.
The most Bren-like of the emergency designs was the Besal, formally approved in 1943 but never made in quantity. The prototype was demonstrated to the Small Arms Committee in March 1942, and subsequently underwent an encouraging trial. It seems to have had a skeletal butt and a fixed pistol grip beneath the rear of the receiver, and cocked by retracting a handle on the front right side of the breech. A revised Besal, submitted in August 1942, was 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 system was clearly inspired by the Besa, which had also drawn inspiration from Czechoslovakia. The improved Besal also had a two-position 'L' type back sight, a simple bipod, and a carrying handle on the barrel.
Few problems were encountered during protracted testing in the winter of 1942 on the ranges at Pendine, so the Besal was adopted as the 'Gun, Light, Machine, Faulkner, .303-inch Mark 1'. By the summer of 1943, however, the likelihood of a German invasion of Britain had passed. As deliveries of Bren Guns from Enfield, Inglis and the Monotype Scheme were more than adequate to meet existing demands, so the introduction of the Faulkner machine-gun was rescinded on 10th June 1943.
Though the Besal operated much like a Bren and locked similarly, by displacing lugs on the bolt into the receiver wall, the return spring had been moved from the butt to a new location inside the piston extension. The perfected gun was 46.5in overall, had a 22-inch barrel, and weighed 21lb without its Bren-type box magazine.
Bren Guns will be encountered on 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 II* of 1944, intended for airborne troops. Among the special anti-aircraft mounts developed during the Second World War were the Motley cradle and the 'Gate', with guns suspended from overhead frames. The Lakeman Mount, a pendent system popular on armoured vehicles in 1940-1, had a large coil spring behind the support arm.
Even the earliest Bren Guns proved to be very efficient, but the magazines were troublesome. The basic design had soon proceeded from the Mk I to the perfected Mk II* by way of Marks I*, I*** and II. Total production of the .303 box magazines was approaching ten million when the war ended. The Enfield factory had been the sole source until May 1939, when new contractors were recruited: the Austin Motor Co. Ltd ('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 was subsequently extended on more than one occasion. Fifteen thousand fourteen-round chargers were made in 19445 by Elkington & Co. Ltd ('M 78') and Lines Bros. Ltd ('S 68').
The success of
the Bren Gun encouraged the British authorities to find it additional roles.
Though the limited capacity of the box magazine was clearly a limiting factor
in any situation which demanded sustained firee.g., infantry support or
anti-aircraft usethe problem had been recognised as early as 1937, when
Vickers-Armstrong supplied six modified sixty-round Vickers-Berthier pan magazines
Two experimental 100-round drum magazines were acquired from the same source in 1938, but were not successful. Eventually, however, a new design was adopted for service. Mark I magazines of this pattern were made by the Austin Motor Co. Ltd ('M 13'), Lines Bros. Ltd ('S 68'), the Vickers-Armstrong factory in Bath ('S 121'), and Wilson & Mathieson ('N 90'); and Mark II examples-with a folding 'L'-shape winding handle-by E.S.S. (Signs) Ltd ('S 223'), V. & N. Huntley ('N 29'), Sigmund Pumps Ltd ('N 65') and Waygood Otis Ltd ('S 292'). Production is said to have approached 950,000, but this may be the total orders instead of actual quantities. In addition, 147,500 filling tools were made in 1941-2, nearly half by Lines Bros. Ltd ('S 68'). A special 200-round High Speed Drum magazine was developed for antiaircraft use, but made only in small numbers.
a Canadian 7.92x57mm version of the Bren Gun, made in quantity for China by
Inglis of Toronto during the Second World War. Note the distinctive straight-sided
The .303 round clearly had no long-term future in British service after 1945, and many British Bren Guns were eventually converted to accord with NATO standards. The Canadians, after experimenting with .280 and .30 T65 Bren adaptations, accepted the heavy-barrelled F.A.L. (which subsequently proved to be a grave error). Ironically, in its Inglis-made form, the Bren Gun had already proven capable of handling cartridges such as the German 7.9mm (known as '7.92mm' in Anglo-Canadian service) and US .3006.
After the experimental .280 round had been abandoned, the British decided to convert the .303 Mk 3 Bren to chamber the standard 7.62x51mm NATO cartridge, an X10E1 prototype being made at Enfield in 1954. It had a modified Canadian 7.92mm breech-block, a barrel rifled with four grooves twisting to the right, and a special thirty-round magazine designated X3E1 (later L3A1).
The conversion was so successful that 1500 guns were converted at Enfield in 1955-7, and issued from November 1957 as 'Guns, Machine, Light, 7.62mm L4Al'. Attempts were also made to adapt the Bren for a sustained-fire machinegun (S.F.M.G.) role, but nothing came of this project or the belt-fed .280 Taden. Designed by Reginald Turpin ('T'), the Armament Design Establishment ('AD') and Enfield ('EN'), this modified tripod mounted belt-fed Bren was replaced in the mid 1950s by another Bren-type S.F.M.G. designated X11. B.S.A. made a single X16, an elegant and allegedly very efficient belt-feed Bren credited to Josef Vesely, but political pressure to adopt the F.N.-designed M.A.G. was too strong.
L4A1 Brens were replaced by an improved X10E2, standardised as the L4A2; nearly
eight thousand were ordered in 1959. The perfected version, the L4A4, is described
in the accompanying Table. The 7.62mm Bren Gun proved most useful during the
South Atlantic campaign of 1982, not least because it could accept the standard
twenty-round LlA1 rifle magazine in an emergency. The L7 GPMG was much more
cumbersome than the Bren in a light support role, but the L4 series has now
been replaced by the 5.56mm L86Al Light Support Weapon
a very poor tool
Bren Gun variants
Experimental adaptations of the Bren made prior to 1939 included 7.92mm D.D./E./2143, developed to standardise ammunition with the Besa. This gun was hastily abandoned when the Second World War began, though trials had already shown its great potential. Enfield converted a few Bren Guns to .30-06 in 1947-8, for delivery to Italy; Brens in this chambering were also made in Canada (very few) and China (large numbers).
C. Mk I. The Canadian
version of the .303 Mark I, made by Inglis in Toronto.
C. Mk I Modified. This was essentially similar to the Enfield-made .303 equivalent.
C. Mk II. This .303 Bren had a distinctive Canadian-made variant of the Mk 3 bipod.
IA. An Indian Army designation applied to conversions of Ishapur-made .303 Mk 3 Bren Guns to handle the 7.62x51mm NATO round. These are currently issued as 'Guns, Machine, Bren, 7.62mm IA'.
L4A1. Approved in 1957, this was a conversion of the .303 Mk 3 Bren Gun to handle NATO-standard 7.62mm ammunition. It accepted an improved L3A2 magazine and was accompanied by two barrels. Most L4A1 guns were subsequently converted to L4A2 standards.
L4A2. Converted from Mk 3 Brens in 195961, this accepted the finalised 7.62mm L4A1 magazine. The extractor and the ejector were improved, the breech-block was modified to make production easier, and changes were made to the magazine-well aperture.
L4A3. This was a variant of the 7.62mm L4A2, issued with a single chromed-bore barrel instead of two standard ones. Converted from the .303 Mk 3, the L4A3 is rare. Only a few hundred were made for British service, all but 134 being sold to Libya in 19612.
L4A4. The standard British 7.62mm Bren Gun, accompanied by a single chrome-lined spare barrel, this was converted from wartime Mk II (rare) or Mk 3 (common) guns in 19601. Seven thousand were made in this way, and another five hundred were assembled from a mixture of newly-made parts and old-but-unused parts taken from store.
L4A5. Converted from the .303 Mk II, this 7.62mm pattern was approved for Naval Service in April 1960. The guns are generally comparable with the L4A4, but were issued with two chromed-bore barrels.
L4A6. Approved in November 1960, this was a 7.62mm L4A1-type gun with the magazine-well aperture altered to accept the perfected L4A1 magazine instead of the L3A2. It also received a new chromed-bore barrel.
L4A7. This was the projected designation for the solitary 7.62mm X10E6 prototype, converted from a Mk I Bren in 1962. The contract was eventually cancelled before any production guns had been made.
Mark I. The original .303 weapon, approved in 1935, this is described in the text.
Mark I (Modified). Introduced in the autumn of 1940, this .303 Bren Gun had an angular (Mk 1*) receiver, lacked the bracket for the optical sight, and the barrel-handle base became a simple welded tube. The butt slide (Mk II) was simplified and a new bipod (Mk II) was fitted. The Mk I (Modified) Bren was made only by Enfield in Britain, though some were subsequently made in Australia in the Lithgow factory. These have Australian Mk 3 bipods.
Mark II. Approved in June 1941 and made exclusively under the Monotype Scheme, this .303 pattern 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.
Mark 2/1. Introduced in 1943, this was simply a .303 Mark II with a modified cocking handle and slide assembly, replacing the simplified fixed pattern developed in 1940.
Mark 3. Approved in May 1944, this .303 gun had a shorter barrel, a lightened receiver, simpler magazine-well and ejection port covers, and a plain (Mk 4) butt. Mk I or Mk 3 bipods were standard.
Mark 4. Approved concurrently with the Mk 3 to conserve supplies of raw material, this had a modified Mk II-type barrel cradle, noticeably less metal in the receiver, and an ultra-short barrel with a new flash-hider.
Manufacturers involved with the Bren Gun
The guns were made by a handful of major contractors, but components and accessories were supplied from a wide variety of sources. The lists below contain details of the most important subcontractors-omitting suppliers of minor parts such as rivets, pins and springs-with details (if known) of their code numbers. The British coding system gave a clue to the general location of the company, as 'M', 'N' and 'S' prefixes signified 'Midland', 'North' and 'South' respectively.
The Austin Motor Co. Ltd made magazine parts and assembly of magazines in the Longbridge Works in Birmingham (code: M 13).
I.L. Berridge & Co. of Leicester (M 601) made extractors and magazine fillers.
Best & Lloyd Ltd of Birmingham (M 30) made the winding handles for the 100-round magazines.
C. & H. Bevens made brackets for the 100-round magazines.
The Bexley Motor Works made piston buffers and catches.
The Bren Manufacturing Company of Gateshead (N 10) made piston parts, sears and associated components, and assembled piston and breech-block units.
British Pressed Panels of Coventry (M 41) made cartridge deflectors.
The British Tabulating Machine Company of Letchworth (S 162) made catches and pins.
The British United Shoe Machinery Company of Leicester (M 603) made extractors. B.S.A. Guns Ltd made butts, bipods, cocking handle, magazine parts, and brackets. The factory has not been identified.
Buckle & Corfield made cocking-handle slide covers.
Hugh Campbell made winding handles for the 100-round magazine.
J. Clark Engineering Co. Ltd of London E.1 (S 25) made front sight protectors.
The Climax Rock Drill Ltd of Carn Brea (S 26) made barrels, gas regulators, front sights, and assembled barrel units.
Coates & Appleby of Birmingham (M 59) made cartridge deflectors.
The Daimler Motor Company Co. Ltd of Coventry or possibly Burton-on-Trent (M 67) assembled bodies, and made locking shoulder screws, ejectors, pins, covers and bipods.
Dernier & Hamlyn made winding handles for the 100-round magazine.
David Dowling & Company of Ilford (S 180) made 'caps, trigger'.
Elkington & Co. Ltd of Birmingham (M 78) made magazine parts and assembled magazines.
The Enfield Tool Manufacturing Co. Ltd made pressings and undertook machining.
E.S.S. (Signs) Ltd of Bristol (S 223) made magazine parts and assembled magazines.
W.G. Evans & Sons made pistol grips and carrying handles.
J. Gibbons Ltd of Wolverhampton (M 88) made nuts and cocking-handle slides.
Gillette Industries made springs, cover plates and guides.
W.W. Greener of Birmingham (M 94) made extension sights.
Halls Telephone Ltd, apparently of Builth Wells (S 420), made cocking-handle slides and assembled tripping levers.
V. & N. Hartley of Oldham (N 29) made magazine parts and assembled magazines.
Arthur Heaton & Co. Ltd of Liversidge (N 179) made magazine platforms.
The Hercules Cycle & Motor Co. Ltd of Birmingham (M 117) made bipod legs, gas cylinders and magazines.
Hindle Auto Products of Bradford (N 178) made magazine platforms.
The Imperial Typewriter Company of Leicester (M 609) made extractor stays.
The Jones Sewing Machine Co. Ltd of Manchester (N 36) made lever change detents and firing pins.
William Jones & Sons Ltd of Birmingham (M 136) made magazine platforms.
Lines Bros. Ltd of Merton, London S.W.19 (S 68), made parts for the 100-round magazine.
Linotype & Machinery Ltd of Altrincham (N 40) made pins, butt slides, triggers, tripping and change levers, springs, plungers and sears.
John McClark of Southfields, London S.W.13 (S 73), made front sight protectors.
The Monotype Corporation Ltd of Salfords, Redhill (S 81), made springs, brackets, back sights, pins, screws, firing pins, extractors, cocking handles, butt plates, plungers, ejection-port covers, Mk III bodies and bipods, and assembled components.
Charles Parks Ltd made front-sight brackets.
The Plessey Co. Ltd made fixed-line sights.
Prince-Smith & Stells of Keighley (N 56) made magazine platforms.
W.G. Pye & Company made collars.
J. Rawson & Sons Ltd of Tunbridge Wells (S 99) made front-sight blades.
The Royal Small Arms Factory, Enfield Lock, made most major components and assembled complete guns.
Sigmund Pumps Ltd of Gateshead (N 65) made piston and 100-round magazine parts, and assembled piston units.
The Silversmiths & Jewellers War Production Group Ltd of London (S 105) made butt-swivel plates and rods.
F. Tibbenham Ltd of Ipswich (S 111) made grips, butts and carrying handles.
Tudor Auto Services made Mk I bipods.
Vickers-Armstrongs Ltd made parts for the 100-round magazines, possibly in Bath (S 121).
Howard Wall Ltd of Hackney, London E.2 (S 123), made magazine parts and nuts, and assembled magazines.
Waygood Otis Ltd of London (S 292) made parts for the 100-round magazines.
Wilson & Mathieson Ltd of Leeds (N 90) made parts for the 100-round magazines.
By far the best source of information is Tom Dugelby's The Bren Gun Saga, published by Collector Grade Publications, Inc., of Toronto in 1986. Miroslav Sada's Ceskoslovenske rucni palne zbrane a kulomety (Prague, 1971) tells the story of the original Czechoslovakian developments, though the language presents a barrier to most British readers. The late Frank Hobart wrote a useful Profile on the Bren Gun, which is occasionally encountered in the hardback compilations produced in the 1970s by Profile Publications. Relevant wartime British manufacturers' codes can be identified from Ian Skennerton's British Small Arms of World War 2 (Margate, Queensland, 1988), which also lists individual production contracts.