Canadian 8mm “Sterile” Bren Gun

This Bren is lot #1013 at Morphy’s April 2019 auction.

The John Inglis company in Toronto first opened in 1859 as a metalworking shop, and grew steadily over the decades under first John Inglis, and then later his sons. Inglis did substantial amounts of military work during World War One, but the Great Depression hit it hard, and both William and Alexander Inglis died in 1935 and 1936 respectively. The company went into receivership but was purchased by one Major James Hahn (DSO) and a group of business partners in November of 1936. Hahn and his associates saw an opportunity to use this large manufacturing facility to make machine guns for the military, and they were successful – in October 1938 they were awarded a contract to make 5000 MkI Bren guns.More contracts would follow, and by the height of World War Two the company had some 15,000 employees and more than a million square feet of floor space.

Among many other projects, Inglis was contracted to make small arms for sale to the Nationalist Chinese government under Chiang Kai Shek – both High Power pistols and Bren guns in 8mm Mauser (to fit the Chinese standardization on that cartridge). A batch of 8mm ZB-30 light machine guns were brought in from the Far East to use as a pattern, and Inglis engineers were able to successfully redesign the Bren to use that cartridge and magazine.

Where the story gets hazy is in trying to determine how many were made and for whom. The Chinese guns are marked in Mandarin on the receivers, and have “CH” prefix serial numbers, like the Chinese contract High Power pistols. However, two additional variations exist without those Chinese markings. Some are marked “7.92 Bren MkI” and “Inglis 1943” (or 44 or 45), and others – like this one – are just marked “7.92 Bren MkI”. The dated ones are typically referred to as Resistance guns, intended to be supplied to European resistance units for whom 7.92mm ammunition was more readily available than .303 – although information on how many guns were supplied in this way (if any) is difficult to find. The last group is generally called “sterile”, and it is not clear what their purpose is. This particular example is one of 23 that were registered in the US in the early 1960s to Interarms, and it does appear that they were associated with some clandestine US military activities. The serial numbers of those 23 Interarms guns range from 1-5343 to 2-8045, suggesting a production of 13,000 or perhaps as many as 28,000 guns – that is quite a lot to be undocumented and missing. 

Hopefully, more information will turn up in the future to shed light on the purpose and use of these 8mm Brens. We do know for sure that many thousands did go to Chinese forces, and some were brought into the UK, where in the 1960s they were used in the development of the 7.62mm NATO L4 version of the Bren.


  1. The serial numbers of those 23 Interarms guns range from 1-5343 to 2-8045, suggesting a production of 13,000 or perhaps as many as 28,000 guns – that is quite a lot to be undocumented and missing.
    So time has come to use … [suspenseful pause] statistics. But keep calm you are not first person to encounter problem in form of I know serial numbers of k examples, but want to know overall production number which is known, due to one of its usage as
    keeping things simple, let
    N be estimate of total production
    m be highest number observed
    k be number of observation
    N = m+(m/k)-1
    Though this will work if and only if numbers starts at 1 and subsequent numbers are assigned to examples.
    In this case we know that k=23 and assuming that sequence starts at 0-0001 then m=28045 thus N = 29263, however if sequence starts at 1-0001 then m=18045 (as we could subtract 10000 from each serial number to full-fill conditions given above), which gives N = 18829.
    That being said, it must be remembered that formula given works properly only for subsequent numbers, therefore if they used some method of deception regarding serial numbers, described method will fail.

    • Maybe they have just randomly assigend serial numbers to the guns? YOu now, to cover up even more. Ans make our heads hurt today.

  2. Ian, by watching Forgotten Weapons and your work pointing out the short comings of the BAR in WWI, is there any particular reason why in the WW2 time frame the U.S. didn’t look at the Bren as the squad Automatic to supplement or possibly replace the BAR. In fact, the BAR fought in Korea and if my understanding is correct, perhaps into the very early stages of Vietnam. One would think that by the end of WW2 the U.S. would have realized the the Bren was superior to the BAR in the way it was used as a “light” machine gun.

    • It’s worth noting that back in 1944 T24 machine gun prototypes were produced in USA:
      Generally speaking it was MG42 slowed-down (lower Rate-of-Fire) and for 7,62×63 cartridge.
      If this project would end successfully then U.S. forces would get weapon which could provide much greater volume of fire than BAR 1918 and also which used more rapid production methods.
      In reality testing showed very poor reliability, so further development would be required, however before that could be undertaken order was given to discard this project.

    • I am no way (not even close) Ian, but give you my view, if you do not mind.
      I do not see BAR in 30.06 substantially different form ZB30 in terms of weight, method and capacity of loading, mobility and terminal effect. In addition U.S. Army supply system in place was used to well proven Browning designs. As you may know, Poland among others adopted BAR in 8mm Mauser as its light-machinegun.

      The only shortcoming I can se is its non-interchangeable barrel, if that had made any real difference.

    • As you said, “by the end of the war”. By the time Army Ordnance realized that the Bren was overall better than the BAR, the question had become moot.

      Also, by then everybody else had realized that the Wehrmacht was right about LMG and GPMG feed systems, and they sensibly wanted the next generation of such to be belt-fed, rather than using box magazines.

      Even before the war, there was already a version of the BAR, the FN (Liege) Model 30, with most of the desirable features of the Bren. After the war, it was reintroduced as the Model D, with the one really useful feature the Bren had that the BAR didn’t; a quick-change barrel. (Although at least some Model 30s had that as an option as far back as 1934, copied directly from the ZB-26.)

      Finally, there was one hurdle to making a Bren in .30-06 that nobody got over; the fact that the receiver and magazine well are too short front-to-back for the 30-06 cartridge. (7.62 x 63mm vs the 7.9 x 57mm Mauser and its siblings, all of which are shorter than it is.)

      A similar problem caused trouble with the one-off U.S. copy of the MG-42 in .30-06, simply because at the time nobody bothered to do any serious measurements.

      The main reason the 7.62 x 51mm NATO cartridge was based on the .300 Savage from the outset was that it could easily be accommodated in actions originally designed for the 7.9 x 57 Mauser and etc.



      • “The main reason the 7.62 x 51mm NATO cartridge was based on the .300 Savage from the outset was that it could easily be accommodated in actions originally designed for the 7.9 x 57 Mauser and etc.”
        So the whole 7,62×51 NATO development was caused by one sloppily executed conversion made back in 1944?

        • Pretty much. Plus the fact that the .30-06 round really isn’t well suited to rapid feed through automatic actions, a fact that was known as far back as WW1.

          The main reason we had reliable .30-06 machine guns wasn’t the cartridge, it was John Moses Browning. I believe the only MGs we had that weren’t at least partly his designs were the Benet-Mercie’ M1909 and the Lewis gun.

          The M1909 worked perfectly well, according to Gen. Julian Hatcher, because it was a Hotchkiss design. The Lewis was fundamentally less reliable, which he learned when he was a captain instructing infantry and cavalry in the use of both at Ft. Hood in 1916.

          Most foreign rifle and MG designs were built around the 7.9 x 57mm between the wars, simply because it was one of the three most common cartridges in use by armies, the other two being the 7.65 x 53mm Mauser and (in the British Empire) the 0.303in Enfield.

          In China, the 7.9 x 57mm was the “default” rifle-caliber round, due to DWM’s “aggressive marketing” prior to the 1925 Revolution.

          By the end of WW2, the 7.9 was pretty much the “world standard” rifle round outside of U.S. and British influence, much as the 7.62 x 39mm is the “world standard” outside of countries that use the 5.56 x 45mm NATO standard round today.

          So when developing a new “standard” round for NATO rifles and MGs in the 1947-51 time frame, yes, one consideration was “Will it work through an action designed for 7.9 x 57mm?”, plus “Can it be made to work in an action designed for 0.303in.?” (Or 7.7 x 56mmR, in metric terms.)

          Because most armies at the time were seeing serious budget cutbacks from their governments. After all, the War To End All Wars (the second one in a generation) had just been won, and aren’t the nasty weapons you have now good enough?

          Those armies were not in a position to buy all-new weapons from the ground up except as the older ones were progressively worn out. Which admittedly was happening faster than the civil paymasters liked, simply because of the heavy use they’d gotten from September 1 1939 to September 3 1945.

          The massive “new buy” of weapons like the FAL, G3, MAG, and etc. in the 1955-65 time frame was motivated as much by attrition of the older weapons as the desire to stay up-to-date in technological terms.

          So whatever cartridge NATO finally standardized on had to do two things; work in the new designs and also work in older designs converted to the new cartridge.

          Hence 7.62 x 51mm.



          • Hatcher presents an interesting mix of objectivity and nationalistic chauvinism.

            I think that the Lewis system has several geometric features which interact to make conversion to 7.62x63mm difficult.

            I think that Hatcher is perhaps apportioning blame in the wrong place, by blaming the gun

            The x62mm to x64mm family of cases on the 12mm head size of the 1888 commission’s 8x57mm… have produced excellent sporting cartridges in both rimless and rimmed form;
            7×64 – everything that the. 280 Remington should have been, but wasn’t, and produced half a century before and after the Remington.
            9.3x62mm a .365″ bore that performs more like .375H&H than it does the .35 Whelen.

            That’s just naming two of the most popular.

            Even if we forget for a moment, Hatcher’s work during ww1, trying to get the 7.62x63mm to perform on a par with the military cartridges of the other allies

            And concentrate on machine gun use, the cartridge was too long

            To achieve a given rate of fire, action parts had to move faster.

            In a gun like the Lewis, that achieved a smoother feed path by putting the bolt locking surfaces behind the magazine opening, the stability and the elasticity of the bolt and receiver demanded that more metal be designed into it.

            And with feeding, as a round is fed from the mag into the chamber, the ends of a longer round must cover a greater distance as the round aligns itself with the axis of the bore
            There is therefore a greater chance of either the case head ducking under the bolt,or the bullet catching on the breech face of the barrel.

            Then there are the problems of weight of gun and ammunition (for less performance than guns firing get the smaller lighter rounds of the ww1 allies), And consumption of scarce resources, needed by other parts of the economy, and by other parts of the stupid war.

            I’ve got to say, the pre ww1 British .276″ project would have been even worse!

          • “And concentrate on machine gun use, the cartridge was too long”
            According to
            Use of the Lewis Gun by the Navy(…)
            The Navy, in its effort to supply the Marine Corps with an adequate light machine gun, had the Marines test the weapon. Complete satisfaction with its performance was expressed.(…)It was realized early that the Lewis gun would best suit Naval needs in World War I for both land and air use.(…)A total of 9,350 guns with spare barrels and accessories was delivered in time for actual service before Armistice Day. All reports concerning use of the Lewis gun under combat conditions stated it was indeed most reliable, and could be fired and serviced by a single gunner. Although jams and stoppages were infrequent, little difficulty was experienced in clearing them when they did occur.
            So it looks that Lewis machine gun could be adopted for 7,62×63 mm cartridge.

          • “And concentrate on machine gun use, the cartridge was too long”
            Anyway if you need cartridge of similar ballistics at muzzle, but shorter than .30-06 (.30 M1 Ball) then grab this:
            it launches 174 gr bullet (of ·303 British Mark VII) at 2750 fps as opposed to 174 gr bullet at 2647 fps. However, I do not know velocity loss rate (negative acceleration in terms of physics textbook) for both, so I do not know how impact velocity would compare with increase of distance.

          • “I’ve got to say, the pre ww1 British .276″ project would have been even worse!”
            Wait. Did British planned to use this particular cartridge in machine guns?

          • It could be and it was adapted to x63mm, but the process of adapting it was long and painful.

            Iirc, Hatcher’s notebook commented that the Lewis design wasn’t up to firing “our vastly superior .30-06”

            Which is an example of Hatcher in his nationalistic and chauvinist mode, wrapped up in a flag, rather than the more objective and rational Hatcher who we see in the chapters on the shortcomings of the 150 grain bullet loadings of 7.62x63mm.

            I think that there were also the problems of personal animosity between Lewis and senior members of the ordnance board (i have a terrible memory for names).

            But, getting back to the subject of the cartridge
            If the united state had simply adopted a x57mm or x53mm rimless case, rather than trying to go bigger and better than anyone else (and, as Hatcher documents, it was only bigger, it wasn’t even as good at long range as .303 mkvii or French 8mm Balle D)

            They would have had a lot simpler time getting good rifles and machine guns.

            Actually, looking at how similar the dimensions and performance are for 7.65x53mm and 7.62x51mm, and knowing that Belgian 1889 contract model Mauser rifles were tested in the 1892 trial that selected the Krag & Jorgensen (and iirc, the second trials that confirmed the Krag).

            I can’t help but be amazed at how much money and effort was put in, over a period of over 60 years, to avoid having a x51mm to x53mm rimless case! Belgium, The Ottoman empire and Argentina, all had an approximation of 7.62x51mm in the 1890s.

            For sporting use, it’s interesting that the 12mm rimless head size, has been taken up to 75mm case length, and rimmed variants are also available (and have been since black powder days).

          • The 174gr .303 Mkvii bullet actually has much better ballistics than its weight alone would suggest.

            This is due to the composite construction with an aluminium or ?wood fibre filler, allowing a longer and more sharply pointed nose, and adequate parallel bearing surface, without adding as much weight as a full length lead core would.

            I did some calcs a couple of years ago, and even launching a mkvii bullet at 2400 fps (.30-30 velocity!) It outperforms the original 150gr. 30-06 load from 800 yards onwards!

            If you are interested, there’s some good stuff on long range ballistics, and also software for estimating aerodynamic drag curves for different bullets over a range of mach numbers

            And using those curves to estimate velocity, trajectory and wind drift

            On Dr Geoffrey Kolb’s website. (He’s got a PhD in physics, was a long range target shooter (1200 yards Palma), established “Border Barrels” he’s since sold that successful business and last I heard, was establishing a business making barrel, chamber and throating reamers).

          • The Rimless .303 is approximately the dimensions of the .30/.284 winchester wildcat

            It looks like it has a slightly longer body, so it will probably have slightly more case capacity than the .30-06.

            There was also the commercial .303 axite, that was a .375 2 1/4″ necked down, that also had approximately. 30-06 case capacity.

    • US Ordnance saw it as a lot of effort, for very little advantage, and not worth gearing up for (the Zb26/Bren family are VERY machining intensive designs) in the middle of WWII. After the war, it ran into NIH and might have threatened the M14 development (which was supposed to replace the M1 Garand, M1/M2 Carbine, M1 and M3 Submachineguns, and BAR… with ONE rifle). It was also contrary to US infantry doctrine (which was based on 2-3 equal strength fire teams who all had superior *total* firepower with semiauto rifles and a light and handy automatic rifle, compared to fewer but better LMGs, more segregated from the riflemen.)

      Yes, a .30-06 Bren, ESPECIALLY if configured in the squad with a 2-3 man gun team, would have been wonderful. But, having two BARs and two identical fireteams (or three and three, in some TO&Es) was pretty good, too.

      Bren would be too heavy to function as a fire team SAW, unlike the BAR.

      OTOH, one or two Bren teams at platoon HQ, somewhat like we used M60 GPMGs when I was in, would have been a fine “GPMG-ish” solution… but would have threatened the M60 program (which was expected to yield a better GPMG than any Bren, being both belt fed and lighter…)

  3. One detail visually different on this J.E.C made gun relative to ZB30 is location of gas tap – it is considerably back from muzzle (closer to chamber). Actually it is quite similar like the one on .303 Bren. This might have produced higher rate of fire than the original ZB30.

    • That’s an interesting point,

      Who exactly were the steriles made for?

      For example what were the materials in the operation Gladio arms caches?

      And how many of those are still at large amongst unsavoury groups?

  4. “Canadian Defence Commodities” 1967 Dept of Defence Production Ottawa states:
    in Canadian Arsenals chapter “recent production has included .50 Brownings, 7.92 Bren LMGs to a foreign account; 7.62 (FN) C1 and C2 rifles and Sterling SMG”.
    Heard a story from good source that c1960 Longbranch made these guns shipped to an RCAF base where they were flown out.

  5. From Chi-com hands to Viet Minh. ZB26s and these gems.

    The BAR is inferior to the Bren because of 1) the location of the magazine, and 2) the decision to not have a crew to serve the gun. Every “squaddie” and “digger” in a Bren gun equipped squad carried extra magazines for it. Not too sure if that ever applied to fire teams with the BAR, although it is certainly possible.

    Sweden also had a BAR with a quick-detach barrel and spares in 6.5x55mm.

    You know, as I watch these videos, I find myself about to say “A-ha! But what about the ZBG-33 prototype?!” only to then have Ian deliver an even more precise appraisal of that very prototype… Good work! Excellent!
    Thanks as always!

  6. Re.Cal .30 Brens…both Italy and ROC developed a .30 cal Bren Gun in the 1950s, by lenghtening the Body to accomodate the longer cartridge and magazine.the Italian one did notget past Prototype , as Italy opted for the MG42/59
    7.62 Nato conversion of the MG 42 guns, and adoption of
    GERMAN MG tactical doctrine.
    The ROC, However, went onto produce the .30 cal Bren as the Type 41,(1952) by Factory 60( Kaosiung, Taiwan) until eventually 7.62 was adopted in 1960s
    ( M14, M60).
    I would assume that the.30
    BREN T41 are still held in reserve, as are the M1 Garands etc, in the ROC.


  7. In 2005 one 7,9 mm BREN made by Inglis was dug out in Warsaw, Poland. MGs like this were being supplied by air to the Armia Krajowa from 1942 onwards. Very few survived to this day. Together with other weapons and ammunition, it was stashed in the cellar of a building by one of the Warsaw uprising units. Well preserved with grease after it was cleaned and brought to the firing condition. The gun was damaged by a rifle round and repaired by unknown AK gunsmith.
    Full article in Polish available in “Problemy Kryminalistyki” [Forensics Issues] online:

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