Semiautomatic Bren from Historic Arms, LLC
By Mark Genovese

The Bren Gun is one of the most recognized Allied weapons to emerge from World War II. Exceedingly robust and well built, it started life in 1924 as the Praga M24 designed by Vaclav Holec of Zbrojovka Brno, the state Armory at Brno Czechoslovakia. After trials, the M24 would be redesigned, and by 1926, it became the ZBvz26. Production began and the weapon became available in large numbers in 1928. With the introduction of the heavier 198-grain 7.92mm bullet versus the early 158-grain bullet, it forced the Holec brothers to redesign and retool their ZBvz26 in order to handle the increased pressure. This improved and strengthened model would become known world wide as the ZBvz30. When World War II started Brno already had as its customers, and was exporting in large numbers to Venezuela, Uruguay, Turkey, Sweden, Spain, Romania, Peru, Lithuania, Yugoslavia, Japan, Iran, Guatemala, Britain, Egypt, China and Chile, just to name a very few.

In the 1920s, the British started their quest to find a suitable replacement for their reliable, but heavy and dated Vickers water-cooled machine gun. The changing times would require a then radical new concept in infantry warfare and a clear departure from the fixed trenches of World War I: the so called Light Machine Gun. The British light machine gun trials would commence in 1930 and would include the Browning BAR in .303, the Darne light machine gun, the Vickers-Berthier light machine gun, the Kiralyi-Ende 7 light machine gun, the Madsen light machine gun and the ZBvz26 light machine gun. Five years would pass before the British would sign a license agreement with Brno for the rights to manufacture and sell the ZBG33 light machine gun, soon to become known to the world as the Bren. The name Bren came about by using the first two letters in Brno, where the weapon was designed, and the first two letters in Enfield, the arsenal where it was manufactured. The first Bren MKI came off the production line at Enfield on September 3, 1937 and was officially approved for British service use on August 1, 1938. Production started that same year at John Inglis Company Ltd. Toronto, Canada with an order of 5,000 weapons. 220,000 MKI Brens were manufactured at Enfield during World War II with the last ones completed in 1946. The receiver manufacture alone was an arduous, difficult and time consuming task in itself. The blank, starting life at 39 pounds, was flame cut from 2-1/2 inch plate and, 247 machining operations later, transformed it into 4-1/2 pounds of industrial art. 362 cutting tools were used and a total of 273 fixtures needed to hold the receiver throughout the manufacturing process and 740 gauges were needed in 18 separate inspection operations. Over 84 British companies were involved with the manufacture of Bren components and/or parts during the war years. The Bren MKI saw its first baptism by fire with the British Expeditionary Force in France from 1939 through 1940 with mixed results. By the time of the Dunkirk evacuation in June of 1940, 30,000 Bren MKIs had been manufactured, and of these, 27,000 were lost in combat. Over its long successful career, the Bren has been fielded in several calibers including 7.92x57 (8mm), .30-06, .280 (7x43mm), 7.62x51(.308 NATO), 7.5x45mm, 7.62x39 and 7.62x54R. After sixty seven years, this outstanding weapon soldiers on today as the L4A3 with several successful belt fed versions having been tested over the years. Characteristics of the .303 Bren light machine gun system of operation include open bolt, gas regulator and select fire. It is 45.5 inches long with a 25-inch barrel, can fire from a 30-round box or 100-round drum magazine and has blade sights with radial drum. The muzzle velocity is 2,440 fps with a rate of fire of 500 rpm. The weight of the gun is 23 pounds.


All Bren kits entering the United States must have their receivers torch cut in three pieces as prescribed by the National Firearms Act, Department of the Treasury Bureau of Alcohol, Tobacco and Firearms. Semiautomatic versions of fully automatic firearms must fire from a closed bolt, not allow any fully automatic parts to fit within them, disconnect after a single pull of the trigger and not be readily restorable to fully automatic operation. Starting with the Historic Arms Bren receiver parts, they have been carefully and meticulously welded within a specialized jig, which minimizes the possibility of distortion during assembly. The left side bolt carrier slot/channel within the receiver has been completely welded closed from front to rear. The BATF approved method of destruction mandates a torch cut through the magazine-well area significantly weakening the tilting bolt locking system. Len Savage (Owner Historic Arms (706) 675-0287 and firearms designer) has addressed this challenge by sandwiching an 1/8 inch thick by 3 inch square plate to the right and left side of the well, professionally beveling the edges and filling in with welding rod, thus rendering an extremely strong and attractive receiver. The forward 14 inches of the lower trigger group have been cut free just in front of the trigger guard and permanently welded in place, making it impossible to re-cut the left bolt carrier slot/channel and use a fully automatic bolt and carrier.

The bolt carrier has been modified by the addition of a recess on the right rear bottom to serve as a locking recess for a locking paw that has been installed on the top right rear surface of the piston assembly. If an illegal alteration was attempted on the disconnector to prevent its function and allow the striker to follow the bolt carrier forward during the firing cycle, the pressure from the striker on the rear of the bolt carrier and piston assembly would cause the locking paw to lift up and enter the recess on the bolt carrier, preventing it from moving to the rear sufficiently for the firing pin to contact the striker. This condition, in conjunction with the 8-1/2 to 9 pound pressure needed to move the firing pin, will prevent the firearm from operating in a fully automatic mode. The operating rod, gas piston, trigger, pistol grip and magazine floor plate have been replaced by domestically manufactured components of the same nomenclature, bringing the total number of imported parts to nine in the final assembly, as listed and detailed in Title 27, CFR Part 178, section 178.39. The bolt carrier has had its left rail completely removed via milling as well as the forward 5 inches of the right side. The bolt carrier piston post cotter is permanently welded in place to prevent an exchange with a full automatic part and the piston tower surface that used to contact the original firing pin has been completely machined away into a groove, end to end, to accommodate the new closed bolt semiautomatic 4-1/2 inch long firing pin, thus rendering a fully automatic firing pin worthless. The longer firing pin overhangs the rear of the bolt by approximately 1/8 inch to allow the new sliding striker to contact the firing pin in the closed bolt position, initiating primer ignition. The Bren stock lower employs the striker recoil spring. Within the trigger group, a simple disconnecting sear replaces the fully automatic parts, slightly repositioned and re welded in such a way that the selector switch cannot be moved into the full auto position. The original bolt recoil spring system has been retained and works perfectly in this conversion.

Even the novice will have absolutely no problem field stripping this weapon for cleaning and maintenance. A single pushpin at the upper rear of the receiver can be removed effortlessly and then simply pull the trigger group recoil spring and stock straight back and off the receiver. Next, the striker will move straight back and out as well. Then, pull the cocking handle back until you can grasp the bolt carrier and bolt and remove to the rear.

I purchased this firearm, through the exclusive distributor of Historic Arms, LLC, from Mr. Phil Thompson, owner of Hit and Run Guns, 4771 Britt Road #E-5, Norcross, GA 30093 (888) 207-2220. It was delivered in three working days packaged in a high quality Winchester gun case. Accessories included two magazines. After purchasing the Bren, I set about the task of bringing in a quantity of surplus .303 British ammunition, as I do for all my firearm projects. To my surprise, very little decent, safe, reliable and affordable surplus .303 is out there; unlike the 8mm available in vast quantity, high quality and very cheap. Most .303 is sixty year old third world surplus made with Cordite which is highly corrosive and unstable. The only alternative was to manufacture new at 50 cents per round: not an appealing alternative. After a long talk about my dilemma with Historic Arms, I was pleasantly surprised to learn that they are the leader in the field of Bren full auto and semi auto caliber conversion.

The 8mm conversion would become a reality because Len had squirreled away two beautiful original Inglis 7.92x57 barrels for himself. After so much pathetic begging on my part, he couldn’t stand it any more, and agreed to take on the project just to shut me up. I was able to locate eight original ZB26/30 magazines, absolutely necessary for this conversion, from Kristin over at I.M.A. Inc. (P.O. Box 256 Millington, NJ 07946 (908) 903-1200). My old friend Dave Michels, of Sarco Inc. (P.O. Box 98 Stirling, NJ 07980 (908) 647-3800) supplied the hard to find 7.92 marked extractors. Historic Arms came up with the magazine catch, ejector and an original 8mm marked MKII sight, in perfect condition. The original 1944 Canadian Inglis 7.92x57 “Chinese Resistance” Bren, manufactured for the Nationalist Chinese Government, used a .303 bolt which worked great for us as well. The only machining necessary Len and his partner John Craig would have to perform for this conversion was to open up the length of the magazine-well just slightly at the rear to accommodate the ZB26/30 ammunition magazine. They took this opportunity to replace my ageing gas cylinder, machine to semiautomatic specifications and head space a second bolt and bolt carrier group, engrave 7.92 to the right side of the receiver to replicate the original “Resistance Bren” and of course a new baked on Dura-coat finish. The two 7.92 Inglis barrels had some light surface pitting due to years of storage. The peripheral hardware was removed from the barrels, installed in a lathe, turned down, then highly polished, serial numbered to the gun and hot blued. I called upon the legendary repair wizard, Mr. Jon Moran of Charlottesville, Virginia (e-mail jon@liberatorcrew.com), maker of resin handles for spade-grips, etc., to put his pattern skills to work and turn replacements for the aged barrel carry handle grip. He chose dark Dogwood, historically used as tool handles due to its hardness and durability, and then buffed to a mythical sheen. Over two hundred Bren kits were sifted through to find the perfect black walnut burl wood to complete this outstanding historic military firearm and veteran of the greatest war.

In less then five minutes one can swap the 7.92 extractor and barrel for .303 and be back in business. Test firing this weapon required absolutely no sight adjustment. Out of the box, one could achieve minute of angle results at 230 yards. 250 rounds of Romanian and 250 rounds of Yugoslavian surplus ammunition were used for the initial test. No failure to feed or failure to extract was noted. What was discovered is the 8mm ammunition has a much more powerful recoil impulse then .303 and the gas regulator must be set at the lowest position before firing the weapon. Once the regulator is set, this firearm is an absolute pleasure to shoot. Considering that transferable Bren Guns are currently selling at auction in the $30,000 plus range, a semiautomatic of this caliber, originality and a manufacturer worth its weight in gold, is a bargain at one-tenth the price at just under $3,000. For those not interested in a World War II correct dated Bren, Historic Arms will be marketing a brand new, C&C machined, receiver in 7.62x39, .308 NATO, 8mm, 7.62x54R and, of course, .303 British. A belt fed version is also in the development stage. An in depth review will be forthcoming when it becomes available.

This article first appeared in Small Arms Review V8N7 (April 2005)
and was posted online on May 31, 2013


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