Browning M2 “Anti-Mechanization Weapon”

During the latter half of the 1930s, the US Cavalry decided to experiment with adapting the .50 caliber Browning M2 heavy machine gun into a bipod-mounted, shoulder-fired configuration. The goal was to devise a variant of the gun that would be more portable and flexible than the standard model with it’s separate tripod. Here is one of the early iterations:

Early M2 Anti-Mechanization Weapon
Photo from Springfield Armory, October 9, 1936. Tech Sgt Lamar with an experimental conversion of the M2. (thanks to Alex for sending it!)

This first version used a pretty much stock early M2 mounted in a spring-loaded soft mount to absorb some of its recoil, and fitted with a large shoulder brace, semiautomatic pistol grip trigger, and hefty bipod. The weapon was also fitted with a T3 prismatic optical sight, the utility of which I would have to question. In a recoiling carriage like this gun has, the optic seems like it would be much more of a hazard to the shooter’s eye on recoil than a helpful sighting aid.

As the experimenting continued, the soft mount was abandoned, and the later versions are actually more akin to normal M2 machine guns with shoulder pads and bipods – longer barrels were also used, probably to help dampen the recoil and blast:

M2 Anti-Mechanization Weapon
Modified Browning M2 with semiauto trigger, 36″ barrel, and T3 optical sight (photo: Goldsmith)
M2 Anti-Mechanization Weapon
Final version of the Anti-Mechanization Weapon, with 45″ barrel in firing position. (photo: Goldsmith)

Presumably, the gunner would have used short belts of ammunition with the guns, since they were not capable of full-auto fire. The targets would probably have been basically the same as the obsolete AT rifles used in WWII, and the anti-material rifles used today – light vehicles, structures like radio transmitters, parked aircraft, etc. Not a bad idea, but the M2 was probably not the best way to approach the goal.

Ultimately, the project was abandoned just before the US entered WWII. The reason was that these modified guns actually wound up being heavier to carry, slower to bring into action and required more space to get the same amount of traverse as a standard M2 and tripod. The problem with weight was that the regular M2 broke down into three piece – action, barrel, and tripod. The experimental guns here all used permanently attached bipods, meaning that while they were about 20 pounds lighter overall, they only broke down into two pieces, and the action was heavier than the standard one. With the final version, the heavier of the components weighed in at a rather staggering 77 pounds – imagine the poor grunt who had to add that to his standard loadout. Now, these were intended to be Cavalry weapons and not Infantry, but with the added broken-down weight they failed to provide an improvement over the existing M2.

Reference:

Goldsmith, Dolf. The Browning Machine Gun: Semper Fi FIFTY: Volume IV. Collector Grade Publications, 2008.

93 Comments

  1. Despite the initial project purposes, this looks pretty much an ancestor of a heavy sniping rifle….it would be nice to have one, now… hi
    N

  2. Fascinating, I had never seen pictures of these brutes, and had no idea the military ever experimented with such things on the M2 platform. They certainly fit the title “Forgotten Weapons”!

    Having seen these, particularly the first picture, I now am curious as to how a similarly made recoil-sled soft mount, “bullpup”, full-auto, shortened and lightened, bipod-mounted, 1919A4 might perform. The 1919A6 was such a long, unwieldy, ugly beast…

    • The Browning M1919A6 is derived from tank-mounted Browning with emergency tripod design primarily to use when crew must abandon their tank.

  3. When I found this photo (the first photo) it looked to me like the ancestor of the Russian Kord infantry machine gun. A very interesting experiment.

    • Given the Kord, I think this concept should be revisited.

      That sort of harness it’s inside on the tech Sgt photo, with modern materials might be the way to go it could hold recoil dampeners etc.

      Full auto might be doable these days…

      Advanced primer ignition, crossed with that Gas break lark from the Steyr GB I was thinking of. The harness would act as a new receiver, you would use M2 internal parts.

      • That was pretty much done with ground use of Becker cannon in WWi and the specifically designed for ground use Oerlikon SSG of 1931 and SSG36 of 1936, all using cannon rounds.

        all were effectively obsolete against battle tanks before the beginning of WWii, although they remain useful against lightly armoured and soft skinned targets up to the present day.

        • I think there’s room Keith in the modern arsenal for a automatic .50Bmg cal individual weapon, firing from say ten round Barret mags as a fire support weapon.

          Thinking along the lines of the Barrett M82A2 bullpup rifle, which goes over your shoulder. But with a detachable barrel, so two guys can carry it’s parts separately.

          A kind of layout as above, but with the reactive counter-recoil tube above the barrel from the Croat Rt20 rifle. In the above configuration most of this recoil device would be over the receiver, and would be attached to it. The barrel would slot into it via a gas port/plug similar to that from a FN mag, at the appropriate point.

          Possibly used in conjunction with, a API bolt system via…

          I also have a notion of making a 12.7x99mm case with a rebated rim for use with a API mechanism, to try this out you could perhaps use .50 Beowulf which already has a rebated rim as is my understanding. Essentially you make a telescopic bolt which fits over the barrel up to the gas plug aforementioned, this particular configuration would entail the barrel having a Steyr GB type gas delay port forward of the chamber as appropriate. This would correspond with the telescopic bolts design, in it’s function. And the bolt would contain the API mechanism, with a suitable trigger mechanism in the receiver.

          Basically it fires from an open bolt, and at the point of ignition “while the bolt is still travelling forward” the telescopic bolts gas dely “grooves” would be aligned with the barrels ports as appropriate, in theory adding to the resistance of recoil until the bolt is fully forward, when it is fully forward some gas will have been diverted all the way through the counter recoil tube at the same point as the bullet leaves the barrel allowing the bolt to recoil under less pressure.

          Repeats until the magazine is empty, with the purpose of keeping the enemies head down while you do something else. Handy to have if you are on foot etc, out and about.

          API, Gas dely bolt cheaper to produce in relation to a open bolt mechanism, and in conjunction with the recoil tube may not make you to a 360• Sonic the Hedgehog flip upon pulling the trigger.

          What y’all think? : )

          • Actually the .50Bmg isn’t suitable for API is it because of the neck, unlike the Beowulf. But you could keep the same’ish case dimensions and taper it up more to have it’s shoulder be of an appropriate size for a .55 cal bullet perhaps.

          • The way around the case shoulder in API is just to cut the shoulder off and to use a sabot to reduce the calibre.

            If you use a Minnie style bullet with a very long skirt, you can get away with minimal rifling and still have better aerodynamics than a “diabolo” type waisted projectile.

            For a half inch browning as the parent case, that becomes very simple, as Browning designed the case as a lengthened and rimless 12 guage, so sabots are available.

          • Also, if you are interested in API, Ian posted a manual for an Oerlikon cannon a while back. It’s also worth reading some of Oerlikon’s patents for striker mechanisms and interlocks to prevent premature firing.

          • .700 Nitro express has a bullet which might be appropriate to pop in the neck of a cut off shoulder of a Bmg case looking at it also, apparently your boffins have come up with “smart” bullets for .50 which would negate only having ten round mags in full auto in conjunction with a personal weapon having manageable recoil pop them in a sabot even in relation to Api aye I saw that booklet Ian put on the site I will have another look.

          • Mind you I still quite like the idea of launching ten unguided thumpers from your shoulder in rapid succession if you could regardless ie. With unguided controllable recoil via some method.

          • To many of the guys above who think some sort of large Sniper Rifle” is the future, look mat this!
            http://www.stellar-exploration.com/#!40mm-guided-grenade
            This is not the first, second or even fifth design to reach T&E including one in 12 gage!
            IIRC, Most of them work off of a Motorola chip manufactured for GM automobile engine management. The same chip is also used to make model aircraft Auto Pilots.
            Guided munitions are coming and their size and price is going down too. Why train a superb sniper at a cost of several tens of thousands of dollars when a $12.00 shell in a $100.00 gun can do the same mission more effectively?

          • A good part of the time, effort and expense in training a qualified sniper lies in tactics, concealment, movement, navigation, self-contained operations and intelligence. The ability to shoot accurately and finally put a round into the intended target is just the end to the means.

            Assuming highly-sophisticated guided munitions become the norm for sniping operations, qualified personnel will still need to undergo the same intensive training, both to get the weapon(s) firing those munitions within final killing range, and to get the most efficient use out of said weapon(s) and munitions under a wide variety of differing tactical circumstances. This would mean fully understanding their limitations and advantages, and being able to work with those characteristics under constantly changing, dynamic battlefield conditions.

          • I can see what you are saying Stewart, but I wasn’t really talking about a sniper rifle anyway, more of a fire support weapon. That Russian gun in the link isn’t a sniper rifle either, I bet that kicks like mule however. So if you could make a less recoiling automatic weapon, that could be carried by two chaps to keep the weight and length down. Given the Russians have a 14 round version, why not make a ten round mag one to match and indeed improve on it’s capabilities.

  4. Who did the Cavalry contract to do the development work on those brutes?

    Surely the Cavalry were aware of contemporary developments, for example the original 1932 Oerlikon SSG 20mm semi auto, at 66 pounds empty, and the upgraded 1936 SSG 36, with its lengthened 20mm cannon round, at 85 pounds but which broke down into 3 lighter assemblies for transport.

    Oerlikon salesmen were very active in all parts of the world in the 1930s, to the extent that Germany, Japan, Britain and the United state, all used Oerlikon and Oerlikon inspired cannon in aircraft and anti aircraft roles during WWii.

    • No idea who actually did the fabrication work – you have a good point about the other options available. I would guess that the military was being typically stingy with money, and preferred to try to use resources already in the inventory rather than buy something new.

      • Springfield Armory did a lot of RDT&E in-house, and they also had a number of local (in western MA and CT, up and down “gun valley”) machine shops that they farmed some toolroom and prototype work out to. This was mainly due to limited capacity at the Armory itself. Some of these shops partnered very closely with Springfield, including feeding back production methods and design improvements.

        Along with the design of the weapons, the Armory also had to work out the production engineering. Probably the key moment that sealed the fate of the Armory was when TRW set up to do the M14 and it became clear how far behind the Armory was in terms of production engineering — but that was circa 1959 or 60, long after this design.

      • Also, the pervasive “Not Made Here” syndrome probably played a part in the decision-making process. It still tends to surface ever so often if given half a chance.

      • Thanks Al, that would make sense. Given the timing, it could well have tied in with one of Hoover or FDR’s “stimulus” schemes too.

  5. The operational problem with these heavy caliber weapons being fired so close to the ground is muzzle blast. Over loose soil and snow they kick up a cloud off the ground obscuring the target and giving away your position.

    • I was surprised they didn’t attempt some sort of muzzle brake, particularly on the first one pictured …not even a beer-can flash hider!

      • Trouble is, it has a recoiling barrel, so the brake would need to be on a barrel shroud that was isolated from the moving barrel.

        If you put the brake on the barrel itself, it would take up the recoil energy which the gun needs to operate.

  6. I wonder if Springfield Armory or some other U.S. organizaton or company was developing a smaller, lighter alternative to this beast in the lead up to WWII, something more along the lines of the Boys Anti-Tank Rifle?

    • Some U.S. forces (notably 1st Special Service Force in the CBI) apparently used the Boys during the war. While not that effective against German armor, the .55in Boys round would have been lethal against the Japanese tanks in the theater, which were mostly the older “tankette” or “machine-gun carrier” types with very thin armor compared to the later European models.

      Quite a few photos of Long Range Desert Group Chevrolet 2cwt trucks in the Western Desert show a Boys mounted or carried onboard. Considering how few German vehicles other than armored cars were vulnerable to that level of weaponry, the most reasonable assumption is that they were being used in the AMR role.

      BTW, the SOE airdropped 63 Boys rifles to the French resistance. Exactly what they used them for, if anything, would be interesting to find out.

      cheers

      eon

      • Not sure what they used them for, but a .55 hole through the coils will ruin just about any transformer in a spectacular fashion.

      • Actually, eon, the Boys was used by the US Marine Raiders in the Pacific, not the CBI. Also, the FSSF only operated in Europe during the war.

        Ian,did you get the other email I sent you?

      • Setting one up in a “blind” near a German airfield could make for an interesting form of “duck hunting”.

  7. Seems like the solution to a non-existing problem. Wouldn’t it be easier to just convert an M2 to a select fire shoulder stock weapon with both bipod and tripod capability, similar to the German approach? Did anyone else use the same weapon as “heavy – tripod mounted” and “light-bipod mounted” like the MG 34 and 42?

  8. As mentioned above, looks like a heavier, less powerful, and even less practical version of developments that were going on elsewhere. Just about everyone in non-Soviet Europe was experimenting with some kind of 2-man portable 20mm bolt or semiauto (for sheer weirdness my vote goes to the full-auto Japanese Type 97) anti-armor rifle and all eventually realized that these weapons may have had “anti-mechanical” uses (trucks, or airplanes on the ground) but did not have enough oomph to deal with anything armored developed after about 1930. And the notion of this being a cavalry weapon… I just have this image of the field trial where the pony soldiers fire 50 or so rounds of full-auto .50, and quickly break the gun down and load it on the horses to move to their next location. In the grand tradition of What Can Go Wrong Will, the scabbard/ carrying case has just enough of a flaw for the hot barrel to give the horse a good branding-iron poke in the flank and half of the weapon takes off at a gallop for the nearest foreign border.

    • That’s if the horse hadn’t already seized the opportunity to bugger off (complete with ammo) when he fired the first shot,

      thus leaving the firer to face the reprisals of the people who’s truck radiator he’s just punctured.

      • And then both sides have to deal with one issue: getting to the town tens of miles away with no real transportation, since the truck is broken and the horse has fled. Unless one of the two parties has a radio set, they are all screwed.
        [scans the trees, hoping that the wolves in continental Europe aren’t nearby]

  9. Keith:
    Where is the information on the Krieghoff Semi-Auto? Krieghoff was working on semi & automatic gas operated falling block action weapons at the time.

    • There are a couple of photos and a very short blurb in Hoffschmidt’s “know your anti tank rifles” booklet on pages 14 and 15, published by Blacksmith corp. I haven’t checked Chinn for any mentions of it yet.

      According to Hoffschmidt, it was gas operated and used a scaled up version of the two part breech lock, used on Krieghoff’s semi auto sporting rifles of the 1930s.

  10. There is some problems which makes the conversion not good idea:
    1.belt-feed is unnecessary for semi-auto weapons its add weight, more elements and more work to build it than simple box-magazine feed
    2.barrel is unnecessary heavy – when firing in semi-auto mode the warming of barrel is a much weaker.
    I think that this project can be canceled due to proposed .90 machine gun T4 in role of anti-tank weapon: http://www.quarry.nildram.co.uk/CAL90.html

    • I think they must have wanted that it in full auto, otherwise what use is it. That T4 page is interesting Daweo, that Croatian 20mm rifle which acts as a sort of recoiless rifle is a good principle I think.

      • Apparently the .90 machine gun was designed as a full-auto weapon because it was anti-aircraft machine gun. I suspect that T4 has rather poor rate of fire because this is typical for long-recoil operated full-auto guns. Despite the U.S. see the need for ~20mm machine gun they don’t have it through entire WWII (the American version of 20mm Hispano-Suiza never works reliable).

        • Daweo, do you “or anyone else” know anything more about the “reactive counter-recoil tube off the Croat Rt20 rifle” so named. I’ve heard of the Venturi effect, in relation to recoiless rifles once. But I don’t really understand, in essence what I am asking is, is it just a tube ported from the barrel ending in a cone or not
          Specifically in relation to the rt20? If so, does some power get lost i.e. it fires a 20mm but not at the same velocity as another method not utilizing said tube. Meaning if it does, would it be better to use a larger round using this method if one was trying to replicate the performance of a .50Bmg, because of some power loss inherent to the system.

          • Yes, it is just a tube with a cone at the back. The tricky part is at the front that you must look closely to see. It is the gas block that diverts much of the propellant gasses out of the BBL into the tube. The one I saw had eight holes in the BBL at 45 degree intervals around the BBL.
            It is not Recoil Free! It is “recoilless” in that it has less recoil than you would think from shooting such a powerful munition. But more than some .50 Caliber Sniper Rifles.

    • Agreed, although the locking set up needs to be just as strong, some parts can be considerably lightened and many parts omitted if the need to withstand full automatic fire and the need to drive a belt feed mechanism are dispensed with.

      Unfortunately the M2’s recoil operation means that it is more difficult to use a muzzel brake to lessen the recoil of a lightened rifle – you’d need to mount the brake on a barrel sleeve that was attched to the receiver casing, rather than the barrel.

      Ian has show a few polished turds over the past few days. This project looks like how to turn something genuinely shiny (an M2) into a turd, then trying to make it shine again.

  11. Interesting. I am sure the U.S. was trying dealing with saving money and the general not-invented-here syndrome. I think Finland had a decent 20mm semi-auto, Lahti?, they used against Russian light armor. It appeared to be reasonably transportable and had capability to be towed by Reindeer. It might of been a contemporary development to the modified M2 pictured though.

    • There were a whole host of similar weight guns to the M2, but firing various 20mm and above cannon rounds that were developed in Europe and Japan at this time.

      Several of them (Oerlikon, Bofors, Madsen and Lahti for starters) would likely have been happy to license their designs to the united state.

      There had also been various “pom pom” rounds in use since the late 19th century which offered far greater destructive power than a half inch Browning, though they were a little over powered for bipod use.

    • IIRC, it was the Finns, (I was wrong, it was the Sweed’s Carl Gustaf M-42) who also had the neatest little 20 MM recoilless rifle! See below;
      During the Second World War the Swedish company Bofors Carl Gustaf developed a small 20 mm device, the 20mm m/42; the British expressed their interest in it, but by that point anti-tank rifles were already out of date.
      And;
      http://www.youtube.com/watch?v=dUoBb3h9HWA&NR=1
      It is a hoot to shoot!

  12. The knowledgeable fellows here on FW have already expressed the wide range of thoughts that went through my head about this one. 77 pounds for the larger and heavier of the two-part weapon? For comparison, the complete M2HB HMG ( with 45″ heavy barrel ), sans M3 tripod ( which weighed 44 pounds by itself ) and ammunition, weighed in at 84 pounds. Enough said.

  13. I always find it interesting when someone refers to equipment as “man portable”. During Gulf War 1, we evaluated the idea of humping our Ma Deuce’s through the mine fields in southern Kuwait. Thank God we opted for a wider breach! Carry the weapon is one thing, but the ammo is always the issue. But then again, back in the 1930’s men were men! I always like the story of the Marine Raider who shot up Japanese seaplanes with a Mauser anti-tank rifle on the Makin Island raid.

      • I remember reading about the Raider use of a Boys on the Makin raid in one of W.E.B Griffin’s “The Corps” pageturners (don’t remember which one; they blend together) but I didn’t know if it is based on historical fact. There are a lot of historic/ gun stuff passages in Griffin’s novels that are flawed. Still, the Raiders did have access to a lot of weapons that the USMC line units didn’t have. Loved AJ’s story about humping the M2 through a minefield as an infantry weapon… would have loved to see the look on the sergeant’s face when the colonel suggested that one.

        Just an odd note… did anyone else notice that according to the photos, senior enlisteds in the pre-war era wore their hair as long as most civilians of the time? The “high and tight” must have been a later uniform requirement. Of course Gulf vets (both I and II) vets are always amazed by the picture of me in my 70s Navy blues because of the hair and beard which were regulation for the time.

        • How about the look on the good Colonel’s face if he were made to hump that M2 exactly as he would have suggested that the EM’s do? THAT would have been priceless, not to mention quite fitting :).

  14. Which heavy weapon would win in a gunnery duel, the M2 anti-tank sniper MG or the Japanese Type 97 Anti-tank cannon? The former is (somehow) easier to carry and easier to charge but the latter has a protective shield and more KABOOM in its shells…

    Or screw all of this and give me the 8.8 cm Flak 36!

    • Try the 8.8cm PaK43 — much lighter and more mobile than a Flak 36 while being a lot harder-hitting — although “portable” in this case is a relative term :)!

      • Thanks, Earl, but I think the PaK 43/41 is more mobile than the original PaK 43 (it’s on a field artillery styled carriage). Anyways, whichever 88 mm gun we use, let it be one with armor penetration in mind. I saw in a web comic a failed attempt to take down a giant monster with a Flak, but that was because the gunner tried to go for a head shot. Had she aimed for the monster’s belly, the armor-piercing shell would have done damage to the point of LUDICROUS GIBS! And of course, for tank shooting (or monster shooting), you need a flak battery, not a single gun. Ask Erwin Rommel, who knew how to deploy tanks and anti-tank guns better than many of his enemies.

        “Rommel… You magnificent bastard, I read your BOOK!”
        ~Patton (film)

        • How fitting, where Rommel and his foresight and ability to effectively adapt and improvise were concerned.

          By the way, I did originally have the compact, lightweight, low-profile Pak 43/41 with split-trail carriage ( probably the best anti-tank gun of the war, period ) in mind when I posted about the “PaK 43”. Sorry for the confusion.

    • Unlikely to happen. If either one was encountered by forces of the other, the default move is to get something much bigger on target to destroy it as fast as possible.

  15. While initiators of tis project might have thought otherwise, this indeed was not best way how to throw M2 ball 1000 yards ahead. Nowadays of course we see a display of .50cal guns doing just that but they are equipped with requisite muzzle brakes such as M82 is. Hard mounted BMG can easily produce up to 6,000 lbs of trunion force, more than is healthy for average user; softer or spring loaded butt makes it easier, but still it’s a bear.

    I recall seeing article, long time ago (have it stored somewhere), describing modifications made to BMG to be shoulder fired to some degree of comfort. Man connected with this research name was Robinson (working for Maremont Corp.?) and in the picture he was shown blasting away standing with gun placed on TOP of his shoulder. There was some sort of recoil-balancing mechanism apparently. So, all kinds of things can be done with some trick built-in. Point is to know what works the best.

    • Of the various cannon derived rifles, the Oerlikons used open bolt firing and advance primer ignition, so that half of the recoil force was spread out before the round had even been fired.

      The Solothurn and lahti (using round with approximately twice the muzzle energy of the Oerlikons) had the whole action run forward and fire when running forward, again to spread the recoil energy which the firer had to endure, over the whole operating cycle, rather than just at the very end when the bolt carrier hit its stop at the back of the receiver.

      In the browning, the reaction of the belt feed mechanism is against the receiver casing (and firer’s shoulder) thus adding additional recoil energy to the poor firer

      • Hi Keith, good to hear of you!

        This is extremely exciting area of research and had been for me for at least past 30 years. As I was involved one time in industry I offered a solution thru my employer to government in that direction – mitigation of felt recoil force for purpose of hit probability improvement. There was not interest in the subject at the time by recipient of proposal.

        Many of those devices you mention are dealing to some degree of success with the issue of mount reaction (recoil force). It is substantial area to study, I did some of it in past and time by time need to go to refresh it so cannot react in detail on spot. However, as you mention quite correctly, the “advanced priming mechanism” caries tremendous promise of efficiency; yet to be developed.

      • Hi Earl, good to hear too!

        I found in meantime some other source (attached below), so you can enjoy some more qualified reading. As a matter of curiosity, colonel Chinn has left R.Robinson’s work completely off. This happened perhaps because his work on “constant recoil gun” remained in conceptual study stage.

        • That’s a really great link, Denny — many thanks! I have heard of, and read about, Russell Robinson’s many historical accomplishments in the field of aeronautics, but have had only fleeting glimpses into his other significant achievements in machine gun technology.

          As with so many other potentially game-changing ideas, it looks as if his concepts fell victim to a combination of bureaucratic and systemic inertia, a narrow-minded “not made here” syndrome, bad market timing and the deeply-rooted, self-serving, established interests of the day.

          What a pity, and what a waste.

          • True, “what a pity, what a waste”. At the same time perhaps better for humanity at least for time being.

            Many ground breaking ideas were unearthed in past and not fully implemented and at the same time much of what industry offers was not for variety of reasons fielded – yet. Military market is definitely of push – not pull type.

  16. The monumental stupidity of various government organizations around the world amazes me to this day. All of this time and effort to duplicate what others had already done, and better too!
    Robert Goddard and friend had designed and tested a Bazooka like rocket launcher during WW-I and it was ready for service before 1919! But wait! We had the Davis gun before the war! And it was a viable Anti-Tank weapon at that time and would have been effective long after ATRs had proven themselves worthless, and it only weighed 40 pounds loaded! More modern ammunition could have kept it viable until late in the war Vs all but a few tanks. ( APCR shot at 1,000 M/S anyone?)

    • Right! The same can be said about Leonid Kurchevsky work on recoilless guns in the inter-war era; the guns were generically named ДРП (DRP, i.e. Dinamoreaktivnaya Pushka. While his larger caliber monsters were a bit over-the-top (to put it mildly… just scroll down to see a 305mm version mounted for experimental purposes on the minesweeper “Engels”), his smaller guns were quite serviceable as infantry support weapons, namely the Model 1935 76mm DRP batallion recoilless gun. A compact, easy to take down version of the later was also produced for airborne troops’ use, well before the German 7.5 cm Leichtgeschütz 40.

  17. And here was I just about to throw Russ Robinson’s CRG .50 into the discussion with a link to that same post 🙂 There was a good two piece article on his work in one of the American gun rags about 20 years ago – Guns & Weapons for Law Enforcement or some predecessor with a simmilar title.

    The internet takes you to some funny places – the .50 rifle.

    http://24.media.tumblr.com/bde64a8fab2ed1be7348493f7582c7f8/tumblr_mjyqxwpHCl1qdzr9to1_1280.jpg

    http://24.media.tumblr.com/879440ec11243b0dcd6eaf6f977ea5b7/tumblr_mjyqxwpHCl1qdzr9to3_1280.jpg

    shane

  18. Interesting. Looking at how many variations this Browning design has been in and tried by the U.S. military, I’m not surprised. I’ve had to work on thousands over the years to include a few prototypes, just in my time. Denny, have you kept up with some of the latest military “advanced priming mechanism” concepts? I’m recently retired from there but I’d like to see where it goes myself.

    • Hi Robert

      I have laid out couple ideas in past and never have felt I quite accomplished what I wanted. One such version, which is more like ‘added mass resisting blow-back’ was the latest. To carry this idea thru and do some meaningful research on it, I believe it would need specific (non-existent at this time) ammunition. If you were interested in personal contact I hope Ian would not mind to mediate.

      • The reason why API, Advanced Primer Ignition and all of those slide forward before it fires weapons will never become “Sniper” type weapons until after the advent of guided munitions is because the forward jump/API upsets the aim and you can’t hit anything with a single shot off hand. Even using a tripod does not help significantly. ( to get the required sub-MOA accuracy!) There is way to much play in the system and moving parts before the shot leaves the BBL.

        • True. I basically agree with that assertion, specifically if you talk about a weapon with point accuracy say out to 800m.

          If you were considering a common type of assault rifle, then it would not matter that much. On general note, there must be always some excess of impulse forward to make it work under all conditions. But it may not be a deal breaker when comes to practical application.

  19. http://en.wikipedia.org/wiki/Davis_gun

    I was looking into the recoil counter balance lark, and found the above.

    Think two guns facing opposite directions joined at the middle, both fire at once. The recoil from the shell “in the gun you want to fire at a target i.e. to the front” is matched by some clutter of the same weight fired out the back simultaneously canceling out the recoil from the front.

    Said clutter disperses behind you…

    Clever, If you look at that wood and canvas sort of plane it’s on you can see perhaps why recoil wasn’t a good thing for the integrity of the weapons mount sort of thing.

  20. Ak107 saw a moving demo video thing of it’s working parts, I wonder if that tech Sgt photos harness gun wasn’t something like that… The M2 barrel recoils doesn’t it, can’t remember, does it? But imagine if it does, what if the idea was for it to “do what it does” but also push the receiver forward of the harness thing at the same time if you follow me.

    Er i.e. Say there was a spring at the front around the barrel, and the barrel had an extension which smacked into the rear of the harness in a manner that made the receiver jump forward.

    Maybe not, anyway fascinating subject.

    • One way or another, you cannot avoid the consequences of “for every action, there is an equal but opposite reaction”.

      If you fire a projectile, you are going to have the same momentum acting backwards as recoil.

      Using a well designed muzzle brake, you can catch much of the hot gas coming out of the barrel and re-direct that backwards (by re-directing it you can capture at best, half of its momentum)

      If you can also accelerate that gas with a correctly designed jet nozzle, you can also harness some of its remaining heat energy as forward thrust, in the same way that the tail pipe of a jet engine generates thrust by accelerating the heated air coming out of the turbine. Recoilless rifles do this by accelerating the propellant gasses out of a carefully designed exhaust nozzle, so that their lesser mass compared to the projectile, is compensated for by greater velocety.

      Redirecting muzzel blast has the disadvantages of stirring up any loose materials, such as sand, snow, or vegetation, and disclosing your position.

      It also directs the blast back towards the firer and his associates, at least increasing the noise experienced, and potentially stunning or permanently injuring an un suspecting associate (there are some youtube vids, which I don’t recommend – of various middle eastern persons getting in the way of the exhaust from rocket/recoiless weapons, and proceeding to meet their 72 virgins).

      Various bipods and tripods, serve to transfer some of the recoil to the ground, depending on how well anchored they are. the large spade like blades which would be effective in soft mud and snow will not be effective in hard or stony ground, and vice versa for the hammered in pegs for stony ground if you are on soft mud or snow.

      Beyond those methods of lessening the recoil reaching the firer

      Come the methods of spreading out the recoil reaching the firer over a longer period of time.

      this is where API / open bolt firing, and various sprung cradles come in. They use a spring or its equivalent ( a buffer, or gas in a cylinder) to store the sharp impulse of the recoil and spread it out more evenly through the operating cycle

      The actual weight of the gun helps here, as mass 1 times velocity 1 equals mass 2 times velocety two – the heavier the gun is relative to the bullet, then the slower it will be travelling in recoil.

      obviously, the heavier the gun is, the more difficult it is to carry around, although you can always improvise by introducing a sand bag – if loose sand is conveniently available…

      With any system of contra moving weights, they must be reacting against something, there is no way for you to use them to actually absorb recoil (ok, you can loose a little energy as heat in a buffer), and that something the weights are reacting against is likely to be your shoulder.

      The best you can achieve with contra moving weights is some storage of recoil energy in order to spread the felt recoil over a longer period of time.

  21. Just re-reading Tigers in the Mud and the author recounts having his tiger disabled by AT rifle round to the Radiator. It was common for them to be deluged with ATR rounds and lose all their vision blocks

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