Burton 1917 Light Machine Rifle

America’s first assault rifle? Well, it does meet all the requirements – select-fire, intermediate cartridge, and shoulder-fired. It was never actually fielded, though.

The Burton Light Machine Rifle was developed during World War One, with the firing model completed in 1917. It was intended as an aircraft observer’s weapon for attacking balloons – a role which required incendiary ammunition.With this in mind, Winchester’s Frank Burton adapted the .351 WSL cartridge from his 1905 and 1907 self-loading rifles into the .345 WSL, with a spitzer bullet. He designed an open-bolt, select-fire shoulder rifle to fire it, which became known as the Light Machine Rifle.

Burton’s rifle was to be usable both in an aircraft where it could be fixed to a Scarff mount for a wide field of fire or used by an individual on the ground, fired from the shoulder. It weighed in at just about 10 pounds (4.5kg) and had a pistol grip and straight-line design to bring the recoil impulse directly into the shooter’s shoulder and minimize rise during automatic fire. The barrel was finned for better cooling, and infantry barrels were equipped with bayonet lugs.

The most distinctive elements of the design, of course, are the dual top-mounted magazines. Each one holds 20 rounds, and each has a pair of locking catches. One position locks the magazine into a feeding position, and the other holds it up above the cycling of the bolt. The idea here was to keep a second loaded magazine easily accessible for an aerial observer – so they could reload without having to find another magazine somewhere in the aircraft. Contrary to some speculation, there is no automatic transition between magazines. When one is empty, the shooter must pull it back to the second locking position (or out of the gun entirely) and then push the second magazine down into feeding position.

Despite Burton’s work – which was well ahead of its time – the LMR had been rendered obsolete for its primary role by the time it was ready. Synchronized, forward-mounted Vickers machine guns firing 11mm incendiary ammunition were being mounted on aircraft, and were more effective on balloons and airplanes than Burton’s weapon would have been. Only this single example was ever made, and it was not presented for infantry consideration as far as I can tell. It was lost for many years before being discovered in a Winchester building, and eventually ending up in the Cody Firearms Museum with the rest of the Winchester factory collection.


  1. Excellent video Ian, glad to see those Patreon funds dig up something so exotic and cool as this.

    Perhaps the bolt is a 2-piece design similar to the Stgw 57, with the firing pin section acting as both a safety and to slightly delay recoil to allow more gases to escape out the barrel.

    • “That should have been the standard US rifle going into WWII!”
      I think Army would not adopt it for wide usage, as being ballistic-wise inferior to their default .30-06 cartridge.

      “.345 WSL, with a spitzer bullet”
      See drawing and photo here: http://www.municion.org/34/345Wsl.htm
      France also experimented with similar cartridge (8x35mm) in Ribeyrolle 1918 automatic carbine but it was not adopted because it was considered ballistic-wise to weak.

      As side note: recently I saw .25-45 SHARPS cartridge. Firstly I think it is old black-powder cartridge which at some point falls into obscurity (like .40-70 SHARPS STRAIGHT), but it was developed recently, in terms of size similar to 5.45×39 or .223 Remington cartridges, this lead to some question:
      -what -45 mean? powder charge in grains (rather not comparing to .30-30 which have -30 and is bigger)? muzzle velocity in some odd units?
      -is any connection between SHARPS in .25-45 SHARPS and SHARPS in .40-70 SHARPS STRAIGHT or they are same only by co-incidence?
      .25-45 Sharps query in wikipedia states it launch 87 gr bullet @ 3000 fps (900 m/s) @ 24″ barrel. How it is possible from such small case capacity?
      -it is wildcat cartridge XOR it is Commission Internationale Permanente pour l’Epreuve des Armes à Feu Portatives recognized cartridge?

      • Hi Daweo,

        .25-45 Sharps is mixing its units
        0.257 inch diameter bullet
        45mm long (.223 / 5.46 x 45mm NATO parent) case

        It’s an adoption (along with SAAMI and CIP standardization of dimensions and pressure levels) of one of the countless and often very good .223 based wildcats

        • “mixing its units”
          I hoped American reached maximal level of chaos in designations, but I was wrong.

          “very good”
          Ballistic data (87 gr @ 3000 fps @ 24″ barrel) look good, even too good for me. Anyone can confirm or deny this numbers?

          • IIRC you can get about 28 grains of powder into .223 case

            compared to about 38 grains into a .250 savage (I’m going from memory, I don’t have either Donnelly (cartridge conversions) or Barnes and Skinner’s Cartridges of the World, to check case volumes or loading data from)

            However 5.56 military loads are typically operating at up to 65,000 PSI, so about 50% less powder but about 50% or 60% more pressure

            It seems that gets you about the same performance as the original 3,000 feet per second 87 grain bullet out of the .250 Savage

            There are potential benefits from going to the smaller case head size, but in this example the increase in pressure is offsetting any gains in reduced bolt backthrust due to the smaller interior of the case.

          • “There are potential benefits from going to the smaller case head size, but in this example the increase in pressure is offsetting any gains in reduced bolt backthrust due to the smaller interior of the case.”
            Still more such rounds will fit in same length magazine (or magazine with same capacity will be shorter)

          • Daweo,
            It’s said the Yanks and the Brits (and the Aussies, etc, ) have a common language between us.
            “All to, [too,] [two,] true, I’m afraid,” said the man with the Tu,To,Two,Tu-ba.
            Welcome to English. :):):)

      • I agree they would not have done so. Institutional inertia kept assault rifles out of the U S inventory until 1965. But imagine this: instead of adopting the Pederson Device, the LAR is chosen for the trench assault role instead. That would put a hundred thousand in inventory, likely less due to cancelled contracts at the end of hostilities. These would then have taken the place of submachineguns in the interwar years, then become the go to weapon for the roles of the M1 carbine, the Thompson SMG and probably a significant part of Lend Lease . Natural selection on the battlefield would take care of the rest.

        • “These would then have taken the place of submachineguns in the interwar years, then become the go to weapon for the roles of the M1 carbine, the Thompson SMG and probably a significant part of Lend Lease”
          Lets assume that this design was manufactured in big quantity, this would probably lead to creation of Thompson SMG derivative for bigger cartridge (there was Thompson and .45 Rem-Thompson cartridge created – http://www.dieselpunks.org/profiles/blogs/thompson-upchambered – 250gr @ 1450 fps) which would become challenger of Burton’s design.

          Also remember that in 1920s-1930s sub-machine guns were considered as a special-purpose weapon and its was used in limited numbers.

          • Yes, a different development for the Thompson is possible. Since this weapon was never developed , we don’t know it’s service characteristics. On the surface it beats the Thompson design on in line recoil control, intermediate rifle cartridge similar to the modern 9x39mm , and simple construction amenable to mass production. If the rifle itself lives up to its apparent advantages, being in inventory already when the Thompson is not, then war time pragmatism during WWII would had guaranteed its success. The sparse usage In the interwar period would not matter much.

  2. Inside the Cody Firearms Museum. I am so jealous. I have been there twice but unlike you I didn’t get to touch anything. Good show!

  3. With a barrel of this lenght and with the nearly equal weight of .45 ACP bullet, the straight blowback operation free from API, should have a respectable level of breechbolt mass and case base web thickness for ensured cycling.

    • From a rough comparison based on video, breechbolt seems having a lenght of 200 milimeters with a 40 milimeters of radius eventualy calculating approximately 1500 grams of weight needing a secure free blowback of 7milimeters. But the breechbolt seems as constructed by two portions which the rear part of it working as a buffer similar to the M16 as descending the cyclic rate of firing at the same time.

  4. Fascinating!
    Lots of clever innovations in that Burton rifle.
    Makes me want to review Burton’s blowback rifles that were manufactured in large numbers.

    Have you considered doing an episode on ready-magazines? :
    Perhaps start with cloth pocket on M-1 Carbine, UZI 90 degree clamp, taping magazines parallel, etc.?
    Consider pros and cons for support troops versus breachers (door kickers) consider how much mud gets stuffed into a downward-facing magazine mouth, etc.

    Meanwhile we are enjoying your pictures of military bicycles.

    Damn you Ian!
    Every time you answer one question, you open up a dozen more questions?
    You are driving curious gun-collectors insane with all your questions!

    • “mud gets stuffed into a downward-facing magazine mouth”
      If you fear that look for 60-round magazine for AK-74, which basically do not only solve this problem but also don’t have to be changed after 30 (or whatever quantity it holds) rounds are fired.

  5. I’ve just had a look for patents, and couldn’t find a thing.

    It would be really interesting to know what is going on inside that bolt.

    The two finger pull to get the gun to fire but only the second finger to keep it firing looks prone to confusion, and ill suited to use with the thick gloves and frozen fingers of a wwi observer

  6. I wonder if they have any documentation on this in the collection? Outside of getting it apart to see, an engineering drawing of the bolt system would be very interesting.

  7. Any thoughts on why the Winchester 1907 didn’t see wider use during world war I?
    Given it’s simple blow back mechanism it seems like it would have been cheap to make and reliable enough for trench warfare. It could have served either as a light semi-auto carbine or, in a select fire version, as a submachine gun. Compared to the MP-18 (the other major submachine gun of the war) ballistic performance would have been significantly greater with the .351 winchester SL cartridge pushing a 12g(180gr) bullet at 570m/s.

    • As a semi-auto carbine or as a select fire version, it has served within French army. But not in wide use. And Ribeyrolles Automatic Carbine (that used a modified version of .351 Winchester SL, previously mentionedby Daweo) was developped for this exact purpose.

      Criticism about ballistics was the relative lack of accuracy over 400m compared to bolt action rifle.

  8. Apart from the strange magazine setup, this piece looks perfect for prison guards and riot police. Military grade full-power rifle ammunition will only make clean-up from riots worse if one counts collateral damage to noncombatants and property! Think about it: Unless you’re shooting it out with a freight-train-load of terrorists armed with RPG-7’s and AK’s firing 7.62×39 AP rounds (which are freakishly expensive and no longer sold commercially here in America), you’d prefer not to turn your surroundings (and tons of civilians) into Swiss cheese!!

  9. Does anyone have any info on the Finnish experimental intermediate round, the 9mm Lilja?

    I’m guessing (which is dangerous) that it might have been based on the basic 7 x 33mm Sako cases before they got necked down.

    One of the editions of Barnes’ Cartridges of the world has a pair of wildcats listed, based on the .223 case and a .338″ /8.59mm spitzer bullet for use in re-barreled .351 Winchester rifles, at a time when .351 wasn’t commercially available

    One with the .223 case cut down and one with it left full length. Barnes reports that head spacing on the case mouth of the full length case was not a success, which isn’t a great surprise, given that the brass in re-formed .223 cartridges would have been stretched very thin.

  10. Something went wrong I could only get the ads and not the video on the Burton , would love to see it .

  11. Just a little peep in notice of the first 11-mm balloon-busting gun, the M1914 Hotchkiss. Both the gun and incendiary ammunition (adapted from the old black-powder Gras rifle) were French developments; US Flying Corps pilots such as Frank Luke flew SPADs mounting one .303 Vickers alongside one 11-mm Hotchkiss. The source I read states that British SPADs (and Camels?) were similarly equipped and that RFC pilots were forbidden from discharging the Hotchkiss at airplanes as a violation of the Geneva Convention! But manned gasbags were a legal target. (From a recent biography of Frank Luke.)

    The one site I was able to find mentioning the source of the 11-mm Vickers states that the French adapted the Vickers to the cartridge and then distributed them to the British, Belgians, et al. The Vickers seems to have been in WWI what the Colt-Browning was in WWII, the universal Allied air armament.

    No disrespect to the Vickers, but as best I can find out, the Hotchkiss was the first successful issued answer to the balloon problem.

    Could the German designers of the MG34 have been aware of Mr. Burton’s weapon? Buttstock, pistol grip, and tubular layout all look disturbingly similar. You could even transpose the saddle drum over the twin box mags.

    • “pilots were forbidden from discharging the Hotchkiss at airplanes as a violation of the Geneva Convention! But manned gasbags were a legal target”
      Interesting: who get such interpretation? I would understand banning firing and infantry at ground but why not against aeroplanes when allow against Zeppelins?

      “No disrespect to the Vickers, but as best I can find out, the Hotchkiss was the first successful issued answer to the balloon problem.”
      states that (British) The War Office see danger of Zeppelin as early as 1913 and this lead to creation of .45 inch Martini Henry Royal Laboratory Flaming Bullet because .303 was too small bullet. I don’t know: in which machine gun it was used and when it was first time against in combat?

      • Early on the main problem was one of power to lift ratios. The early “buses” had such a narrow speed range between maximum level flight and stall that even in banks a little down elevator was necessary. Louis Strange was reprimanded for attempting an intercept with a Lewis machine gun in his Farman aircraft. The weight of the gun so limited the rate of climb and maximum altitude of the Farman that he could not attain the eyeballed 5,000 foot altitude of the German observation aircraft. He was reprimanded because with the equipment available a machine gun could not be flown in the aircraft, Farman, high and fast enough to intercept. The Zeppelins and Schotte-Lanz derrigables were originally to be attacked from above with gravity bombs!! Rex Warneford, a lieutenant in the RNAS, flying a Morane-Saulnier actually shot down a Zeppelin in 1915 by bombing it from above, when his carbine was ineffective!

        • Last time I checked, observation balloon crews and Zeppelin crews were among the only personnel in the German Empire to receive parachutes (fighter pilots eventually got some as well). Setting an opponent’s aircraft on fire while he had no real means of escape usually doomed the victim to a very slow and agonizing death (several pilots shot themselves before the fire consumed everything). In most cases of burning airplanes in no-man’s land, the infantry from the team opposing the pilot of the burning airplane will probably shoot him or worse, throw him back into the wreckage to be incinerated… Or am I wrong?

  12. A very elegant weapon for its time. It brings to mind another ‘forgotten’ weapon of that era, the Australian McCrudden light machine gun, developed in about 1921 by a WW1 veteran. It went to Britain for development and trials but was found to be unsatisfactory. There is quite a bit about it on the Powerhouse Museum (Sydney) website.

      • Mrmax, you can find it easily, along with several other references to it, by just Googling ‘Australian McCrudden machine gun’. However, the museum website is ‘www.powerhousemuseum.com/collection/database/?irn=11405’ . Hope that helps.

  13. Just as an observation…
    As I recall, The Geneva Convention[s] everyone is referring to do not address small-arms or ammunition in any way. Treatment of POW’s, yes, Civilian populations, yes, and, as I recall, poison gas,
    You’re thinking of the number of the ongoing Hague Conventions.
    This all from memory since I have neither the time nor inclination to look it up, but it’s easy to research this common misconception. There are some very interesting wrinkles involving the post-WW2 war criminal trials and particularly the Japanese attempts to justify their war crimes by claiming not having signed the Geneva Conventions exempted them from adherence. Since most of the criminals were hanged, this proved not a popular legal tactic for the defense. Read up and find just why.
    It’s interesting.

  14. The ker-clack when the bolt goes into battery would be consistent with a spring “set” firing pin block. At 14:40 the extractor hook seems to be outside of the cylinder where the cartridge would be. Possibly this is the initiator for clearing the firing pin block. If the outside of the extractor hook hit a projection in the chamber’s extractor cut, it could be tripped, snapping into the extractor groove while the tail moved out of the firing pin’s way. Just a guess, and there are probably hundreds of ways to make the bolt operate as it does.

    • Incidentally there is a simple way to make my above comment look like drivel. I assume the extractor is pre-ker-clack, that the bolt was locked to the rear when the barrel was removed. A post ker-clack picture would have the extractor hook closer to the firing pin hole.

  15. On Firefox. Add played but video did not. Went to the Full 30 link and it ran. I saved that encase I have that issue in the future.

    I’m surprised that was never offered for ground use. Would it have worked in 30-06? It would have been much superior to the BAR IMHO.

    • Completely different. But that doesn’t mean that Ian shouldn’t go visit it over at the Springfield Armory Museum. ^__^

  16. Video as well as last….does not work for me on android. advertisement works fine then nothing. Please fix it.

  17. Just imagine the poor British troops could have been equipped with these for t he walking fire role on the Somme.

    In my opinion, the Western Allies had sought fundamental answers for the bloodletting during the Anglo-Boer War. Bureaucracy will destroy the impulse all the same at the expense of the bloody infantry. This is just one of the what-ifs of history.

    This was the principal reason the Soviets could successfully withstand the Germans during the second world war; the principal reason being that they reconditioned all their LMGs for infantry deployment after further field testing on the Chinese-Mongolian border wars.

    Just imagine the British had belt fed LMGs or enough Brens…they may have been able to hold up the Nazi advance during the Western campaign of 1940 and I am still of the opinion the Desert Rats could have put in a far more effective opposition to the DAK in North Africa.

    So many people would not have been lost in WW2.

    On the other hand, the Japanese NCOS manned the Juki Lmgs like the Nambu for counterstrikes against the superlative American firepower…ensuring more casualties against the Allies in the Pacific; no wonder it took four long years for the Western Allies to push them out completely. Contrast that with the marked entry of the Soviet forces in Manchuria in 1945, in less than five days they had dislodged the Kuomintang who had not lost any of their fierce martial spirit. Yamashita had gathered all the light automatics and LMGS from the Mongolian/Manchurian/Chinese fronts to muster a great defence of the Phillipine mountains in 1945. They stemmed and held off the Americans for months. He chose to surrender but that did not mean he could not have maintained the defence for many more months. He still had a lot of ammunition. Interestingly one of the reasons for this man to surrender was a tactile appreciation that his warnings that the Japanese must modernise before joining in the war had gone unheeded. In my view this was one of the few instances where the Japanese used full automatic fire to stem the allied advances. They, the Japanese, are the best infantry men of the whole war.

    I have not forgotten how the Japanese military advisors who were officers used the power of the LMG to hold off if not inflict severe reverses on the Soviet Led Mongolian forces during the incidents on the Manchurian/Mongolian border. I have done some research, bro.

    • Would it have changed the logistics of the battles, no. The concept of walking fire as presented by the BAR which included an ammo belt with a cup for the butt; to reside in; lacked logical common sense in Marksmanship. What were talking about is shooting from the hip at distance vs a fixed Maxim directing controlled fire. Firstly the Burton nor the BAR users could have brought enough fire power with them as they crossed the battle field to have had any real effect, running and shooting from the hip is fanciful thinking. Well, anyway they thought trench warfare was a good idea, that was proven wrong as well.

  18. Just imagine there is the automatic transition of one magazine to the other, this could only have been ideal for full automatic rifle fire to challenge the supremacy of the GPMGs.

    For a two-man crew, they could still reload even under fire by simply pushing a magazine into the empty one and still maintain a higher volume of assault or defensive power.

    Of course the weights of both magazines will help to balance weight of the receiver; at the same time it will make quite distinctive the low profile of the gun, allowing space for the operator to peer and aim.

    Heat transfer to the barrel during continuous fire could be managed but by this stage of the war, multiple chamber magazines were being slowly superseded by belt feed designs; the latter could offer a full sustained fire role, each belt could manage to feed two hundred rounds per belt. Belts could be stowed in limited space than the magazines.

  19. By order of Stalin the rear gunner was removed from the IL-2 for a short period of time, lesson learnt.
    The 3ed Boar war and the Spanish American wars taught both powers that a standing army with out justification was not economical and military expenditures were low. This led to the slow adoption of the MG’s of that era but both powers instituted civilian marksmanship programs for future instructors and marksmen. This starts to separate some of the European countries that didn’t and this is one aspect of gun laws and civilian marksmanship that is completely over looked and should be historically researched.

  20. I think that the butterfly-layout twin magazine idea could have been an interesting solution for an LMG, and I am surprised no-one else tried it – possibly because the Burton gun was little known at the time.

    Compared with a single top-mounted magazine (Bren etc), the twin layout would have permitted straight-through ambidextrous sights, a higher total mag capacity while still keeping the overall height low, continuous fire without a pause for reloading, and the possibility of using the same magazines in a self-loading rifle.

    The disadvantages would have been a rather more awkward layout for carrying, and an assistant gunner would have been helpful for quick changes of the right-side magazine (assuming a right-handed gunner).

    The feed-change mechanism could have been improved. I have in mind a lever which protrudes vertically upwards when neither magazine is engaged (it would block the sights, so the gunner would realise the situation) which could be rotated to the right to pull the right-side magazine down into engagement, and to the left to switch over to the left-side magazine.

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