Maxim PomPom 37mm Machine Gun

“Pom-Pom” was the name given to the 37mm Maxim gun by the Boers of South Africa, based on the gun’s sound. It was a Maxim machine gun scaled up to the quite impressive 37mm caliber, intended primarily for naval use defending large vessels against small torpedo boats. This particular example is serial number 2024, made in 1889 and then sold three times before being ultimately purchased by the United States Coast Guard and installed on the USS Manning (along with a second gun, number 2026). The Manning was promptly put into military service by the Navy and steamed down to Cuba, where it participated in the first bombardment of Cuba during the Spanish-American War.

These 37mm guns could fire a wide variety of projectiles, including solid rounds which could pierce an inch (25mm) of iron armor at 100 yards and hollow rounds filled with black powder and fused to explode on impact. During World War One, they would be pushed into anti-aircraft service, with the explosive rounds being extremely effective on early aircraft (when you could get a hit, anyway).


  1. Ian, the use of the Pom-Pom was ineffective against Zeppelins as the shells couldn’t reach the latter’s bombing altitude. The HE shells had no time fuses and often came down on civilians, making quite the mess!

  2. I was under the impression that the Pom Poms were ineffective against Zeppelins because the shells would not detonate against the Zeppelin’s fabric covering.

    • There was a liquid filled incendiary round it had a small orifice in the base of the projectile the sealing agent would burn off on firing and ignight the liquid trailing out the base… these worked on any gas filled bag……

    • They were also quite effective “medicine” vs. German strafers. The Junkers J.1 all-metal monoplane strafer, known as the “furniture van” for its handling (rather like a Mack truck) was developed at least partly due to the one-pounder being able to blow most German ground strafers out of the sky with one hit.



      • “Junkers J.1”
        Junkers J.I (Roman numeral, 1917 sesquiplane) or Junkers J 1 (Latin numeral, 1915 monoplane)?
        Anyway, with First World War technology, I don’t see possibility of building one-engine aeroplane immune to 37mm cannon shells.

        • J.I, with a Roman numeral. The original J.1 was a fighter prototype. The 37mm Pom-Pom shells apparently had black powder as the explosive filler, so they weren’t real HE shells, which might enable the J.I to survive a single hit. With actual high explosive filler there probably weren’t many single engine airplanes capable of surviving a 37mm HE shell hit even in WW2. The Il-2 was very resistant to 20mm hits, but 37mm is in different class. Even the “modern” A-10 was designed to survive “only” 23mm hits (both HE and AP at typical ranges).

  3. You need to be very careful with some of the shells for these cannon. The Semi Armour Piercing shells had a base fuze that looks very much like a tracer or base plug. They are powder filled and the brass plug is a fully functioning fuze!

    The handy size of the rounds made them a favorite war souvenir and many adorned the mantelpieces in the 1920s.. More than one resulted in the destruction of the room!

  4. The 1894 catalogue of the manufacture francais d’armes has an add for a single shot 35 mm canon that could be mounted on a yacht
    The gun was 1m70 long and originally intented for market hunting of ducks The version for protecting yachts came with a bullet mould for producing solid shot
    It used a turned steel case 15 cm long charged with 80 grams black powder
    The lead bullet weighed 1kg250 gms and was effective out to 2500 metres
    So even if you couldn’t afford a pom pom and although the add does exagerate the effectife ditance you could still cruise abroad without fear

    • “Punt guns” (so named for the boat they were mounted on, not the maneuver in American-rules football), were quite common with market hunters going back to muzzle-loader days. Some were even improvised from gas pipe or the like after their use became illegal in most Western countries, although they are technically still allowed in the UK as long as the bore does not exceed 1.75″ (45mm).

      Interestingly enough, the United States banned their use for “market hunting” in 1900;



      • Some even bigger punt guns:

        I would guess that a punt gun could presumably also double as a wall gun, rampart gun, or jingal gun if loaded with a slug instead of shot — and vice versa. I don’t know if there was really any intrinsic difference between them, other than their intended use. Or for that matter, the minimum size of a “punt gun” before it might more properly be called a large shotgun (maybe an antique 8 or 10 bore muzzle loading shotgun just sells better when marketed as a “punt gun”?).

          • Ah, Daweo, a design by the itinerant ethnic-Czech designers, Sylvestr and Karel Krnka. Sylvestr designed that fortress gun and a breechloading rifle for Russia, and his son Karel designed guns that were sponsored by Roth and made by Steyr.

        • I think the most obvious difference is that a punt gun is just too long and heavy to e fired in any way except from some sort of rest, whether it has a shoulder stock or not.

          Even “wall guns” didn’t generally have barrels in excess of six feet in length.



  5. From 2:20 in the video:

    “This would go through an inch of cast iron plate at a hundred yards”

    Typical grey cast iron tends to be quite brittle and easily shattered by gunfire, or even a hammer blow. Fortunately, the 19th century ironclad ships used wrought iron instead of cast iron — but unfortunately, the science of metallurgy and manufacturing QC being quite rudimentary, product quality tended to be rather hit or miss.

    The auction’s description page states that this big-bore machine gun is exempt from all NFA categories. But it doesn’t say if this is due to its age and antiquity, or because it is non-functional due to missing parts, or perhaps even due to both conditions. At any rate, this gun appears to be a non-demilled demil that could therefore easily be remilled by just dropping in a few parts.

    … you might need a bigger living room … you might want to talk to your wife …

    As in … talk to your wife about moving out — to make room for this beast.

    • Could be a DEWAT, though that would still be NFA, just without a tax and transferred on a Form 5. If you want to reactivate a DEWAT, it’s a $200 tax and a Form 1.

  6. I LOVE Pom Poms!

    They were widely used as short range A/A armament on naval vessels until the development of the Bofors and other auto-cannon.

    Regarding the name, I believe that I read that it came from Black Africans rather than Boers.

      • A defective Pom Pom gun on a Royal Navy tugboat is a central plot device in the movie “The Key” starring Sophia Loren, William Holden and Jack Hawkins.

      • It was also widely used by the Italian Royal Navy (RM) in the 1930s. The Italian guns were based on the earlier Mk II*C, but fired an improved, somewhat higher velocity loading. Not to be confused with the WW2 British HV round, which had an even higher muzzle velocity.

  7. I found a document that listed the contract price for these things from Maxim-Nordenfelt in 1897 to the U.S.: $2329.72

    Plugged that into an inflation calculator and got 2015 US Dollars: $63,546.76

    I’ll take two! ^__^

  8. Hi Ian, one of the relics is in a tiny intersection island in the village of Seabrook, NH. It is in surprisingly complete condition despite having been outside since, I think, the WWI memorial went up. Maybe 85-90 years. It has the remnants of a different sighting system.

    Where is the Maxim serial number found on the gun in Julia’s possession? I can’t recall if I ran pictures of this gun on weaponsman before. I’ll drive by and take some snaps of it, if I haven’t already.

    This is one in a place that anyone can go up and have a close look at it, if they happen to be in the NH Seacoast area.

  9. There seem to be very few successful auto-cannons based on rifle-caliber infantry machineguns. The Maxim, Vickers, Hotchkiss, and Browning actions seem to me the most successful infantry machinegun designs for adaptation into auto-cannons.

    The Vickers QF 2-pounder naval quad-mount was one of the largest applications of what was more or less a variation of a half-century old design, but sadly lost to the Bofors in practical rate of fire, range, and destructive effects upon targeted aircraft. The Japanese Army Air Force’s 20mm Browning action Ho-5 is another example done in complete ignorance of the US Army’s insistence of the “impossibility” of adapting infantry machinegun designs to automatic artillery, and indeed the Browning action was adapted to 37mm as the Ho-204 if I’m not mistaken.

    The most applicable Hotchkiss large caliber automatic weapons I can think of are the 25mm and 37mm anti-air guns (not the infantry support version 37mm Hotchkiss cannon with strip feed), but these were magazine fed weapons unable to keep up with faster ground attack planes…

    Italy: 20mm Scotti and Breda cannons were both strip-fed and based on actions coming from rifle-caliber machineguns (or an 8×59 “heavy” in the case of the Breda). The former was cheaper, but the latter was more effective at deterring low altitude air strikes…

    Did I miss anything or mess up?

    • The 20mm Breda M35 was an enlarged version of the 13.2mm M31, which in turn was pretty much a direct copy of a Hotchkiss HMG in the same caliber. So, it was not based on the 8mm Mod. 37 machine gun, but belonged to the Hotchkiss family of gas-operated automatic guns.

      To my knowledge the 20mm Scotti-IF was not directly based on any rifle-caliber weapon. Its initial development goes back all to way to 1918 and experiments with aircraft autocannons.

      Magazine feed in AA guns is not as good as belt, strip or hopper, but the magazine changes were a much bigger problem in naval than on ground based applications. AA guns on ground often did not have the opportunity to fire long continuous fire in any case, because trees and terrain features (e.g. hills) would mask the target. Of course there are also many places with wide open plains, where continuous fire could be delivered, so magazine feed was overall still not as good as other feed systems.

      Did the US Army have much use for automatic cannons in WW2? The USAAC/USAAF seems to have preferred heavy machine guns by choice rather than lack of suitable autocannons, and US ground vehicles went straight from .50 cal M2 HMG to 37mm high velocity guns. No other country had larger than 20mm autocannons as vehicle armaments, either, unless self-propelled AA guns are counted. The Soviets experimented with 23mm and 37mm autocannons on light tanks (developments of the T-60), but they were abandoned, apparently because the powder gases would make the life of the commander-gunner quite unpleasant and powerful forced ventilation was not practical (in the winter in particular).

      • “No other country had larger than 20mm autocannons as vehicle armaments”
        Switzerland have: LTH tank armed with 24mm with capacity of 6 cartridge, see photos here:

        “apparently because the powder gases would make the life of the commander-gunner quite unpleasant and powerful forced ventilation was not practical (in the winter in particular)”
        In case of 23mm problem was that recoil of gun used (23mm VYa adopted for tank use) was so big that turret was jammed (unable to rotate)

        “lack of suitable autocannons”
        US industry tried to produce 20mm Hispano-Suiza autocannon, but there were of low reliability, attempts to solve this, but despite changes made it never attain good reliability

        Notice also that all version of P38 Lightning mentioned in table here (F,G,H,J,L):
        has one 20mm cannon, so if it wasn’t deleted in later version it must be considered valuable

        • Those pesky Swiss, always ruining one’s categorical statements…

          About the US use of the Hispano autocannons: the AN/M3 was reliable enough to arm almost all US Navy fighters from 1946 onwards until early 1950s, but the USAF still kept using the .50 cal, albeit improved as the faster-firing M3.

          There was also the T17 project, which derived from the MG 151 but chambered for the US .60 cal cartridge, which was originally developed for AT rifles. The goal was to improve throw weight and muzzle velocity, and enable HE shells without sacrificing muzzle velocity or rate of fire compared to the .50 M2. The T17 worked acceptably, but in the end USAAF chose the .50 cal M3 anyway, probably because the final version of the T17 could do only 700 rpm as opposed to the 800 rpm of the M2 and 1,200 rpm of the M3.

        • The P-61 “Black Widow” night fighter was armed with 20 mm cannon. The Bell Aracobra and Supercobras were armed with cannon as well, although most of those went to Russia where they were better appreciated. The P-61 did not enter service until 1944 and the P-38 held onto its 20mm in later versions. I don’t think there was a doctrine against cannon, but a realization that the US fighter planes were being used mainly to fight other fighter planes, not bombers. Six or more 50 calibers firing simultaneously were thought to be appropriate to shoot down other fighter planes. It could also have been that when undergoing the G-forces of a dog fight that 50’s were less likely to jam, and if they did one had spares.

      • “37mm autocannons on light tanks (developments of the T-60)”
        There was T-70 tank derivate – AA vehicle – armed with single Sh-37 cannon, see photo here:
        but this gun (Sh-37, originally designed as aircraft gun) never worked reliably.
        Sh-37 was replaced by more reliable NS-37 in aircraft application.
        Eventually Red Army adopted ZSU-37 self-propelled AA gun, which was self-propelled version of towed 37mm gun 61-K, but ZSU-37 production started too late for combat usage during WW2:

      • “lack of suitable autocannons, and US ground vehicles went straight from .50 cal M2 HMG to 37mm high velocity guns”
        USAAF also apparently try to counter lack of autocannons working as intended, by using multiple .50″ guns, for example A-26 Avenger might be equipped with:
        a) 8 x .50″ gun in nose
        b) 8 x .50″ gun under wings
        c) 2 x 3 x .50″ gun in outer wings panel (? exclusive with b ?)
        d) 2 x .50″ gun (turret, dorsal)
        e) 2 x .50″ gun (turret, ventral)
        total: 22 guns fixed, 4 guns in turret
        However I don’t know how it was used in reality.

          • Autocannons are highly effective against infantry in the open or in civilian buildings. Entrenched infantry, on the other hand, is very well protected anything smaller than about 65mm HE shells, unless the shells fall in at high angles.

            37-57 mm tank gun HE shells were useful for reducing specific targets such as machine gun nests or towed AT gun positions, and of course against infantry in the open, especially with canister, but it appears that autocannons were even more effective against infantry. Case in point: post-WW2 IFVs nearly all have an autocannon instead of less than 75mm single shot gun. The BMP-1 is a notable exception with its 73mm gun-launcher, but it proved to be less than ideal in practice, and its above the 65mm “rule-of-thumb” in any case.

          • “Case in point: post-WW2 IFVs nearly all have an autocannon instead of less than 75mm single shot gun. ”
            Yes but rather of 30mm caliber than 20mm caliber
            (Germany: MK 30 Mauser, Soviet Union: 30mm 2A42 and 30mm 2A72, Great Britain: RARDEN)

          • Marder 1: 20mm Rh 202. AMX-10P: 20mm M693. M2 Bradley: 25mm M242.

            Thr Germand used 20mm autocannons already on the Schutzenpanzer (APC) kurz (short) and lang (long) HS-30, which were not yet really IFVs due to light armor.

  10. Would you know someone in Seabrook with an 18 ton truck and a large forklift
    No seriously considering the value of these relics they must go missing at times
    I grew up in in Harriston ont canada and next to the townhall there is anice french 75
    Maybe Ian could take a road trip and catalogue these different guns

  11. Wouldn’t this still be NFA? The pre-1899 antique thing only applies to the GCA definition of “firearm”, not the NFA one.

  12. Wow, what a conversation piece! An excellent video as well, shame the gun was missing bits. A very sound explanation of why so much brass was used on these things, remember that the fatigue life of brass is quite low, so you need thicker sections, which are easier to cast anyway, even if heavier, but there was no shortage of bodies to carry stuff then was there? This is all before the discovery of high speed tool steels. The cutters in the 19th century would be carbon steel, hardened and tempered of course, but very limited in their maximum cutting speed. Also sharpening had to be done under a stream of cooling water. This is the main reason why machined steel parts were kept as few as possible, in any machine. Lathes and milling machines were slow, so you had to have many as well as trained operators.
    The 2-pounder anti-aircraft weapon, used rarely as a single mount, usually in 2, 4 or 8 mounts was 40 mm in caliber, like the Bofors, and if a shell made contact it made a mess of almost any aircraft. They were belt fed and water-cooled so they could keep up a high continuous rate of fire. The trouble was its low muzzle velocity (and at one point lack of tracer ammo, which is strange), so apart from the shorter range, predicting where an aircraft will be by the time the shells got there, and feeding the required correction to the sighting mechanism was more error-prone than for higher velocity weapons like the Bofors, which incidentally was in service with the British Army and RAF from the start. When the USA realized that their pre-war shipboard anti-aircraft weapons were useless, and looking at what the Japanese had achieved using naval aviation, they were looking for an upgrade. The British tried hard to sell them the pom-pom, it would be so convenient to have the same ammo, and have guns made in the US if necessary. However the USN had its doubts, the clincher was that the pom-pom would only work with cordite, and there was not a single factory in the USA making the stuff. So they chose the Bofors, which was very wise. The British gradually changed over to the Bofors also, the issue was muzzle velocity and low spread of shot. The destructive power of the round was about the same, and the rate of fire had been addressed by multiple mountings. The pom-pom still had the advantages of belt feed and water cooling. The Bofors used a nitocellulose based propellant which was also made in Britain (as also the propellants for the Besa 7.92 mm Mauser, 15 mm and 20 mm Hispano) although I read somewhere that initially shells came from Sweden.

    • The 2 pdr AA gun was used extensively in single mounts by the RN in WW1 and 1920s, and by the RM (Italian Royal Navy) in the 1930s, and even during WW2, although it was being replaced by the higher velocity Breda 37mm gun. The Italians did not use cordite but some nitrocellulose based propellant, most likely ballistite. Cordite was originally an attempt to work around Nobel’s patents on ballistite and had similar, but overall somewhat inferior properties, so using ballistite instead of cordite was probably not a big deal. The Italian loading had a slightly higher muzzle velocity than the British pre-WW2 loading (later known as Low Velocity after the development of the High Velocity loading).

      The USN decision to abandon their pre-war 1.1″ AA gun seems to have been somewhat hasty. The gun had many teething problems, but by 1941 they were essentially solved. While the 1.1″ was no match to the 40mm Bofors, it did have a better effective range than the 20mm Oerlikons later used. Their range was clearly insufficient against Kamikaze attacks and very marginal even against conventional torpedo and dive bombers.

  13. Incidentally the Maxim-Nordenfelt company was British, not American, so you should have a Union Jack on the opening shot of the video rather than the Stars and Stripes.
    Admittedly Hiram Maxim was born American but he naturalized himself British, like someone once said, to have been born British in the Victorian era was like being given a winning lottery ticket! Wise man, old Hiram, even if a bit cranky. The money he spent on flying machines, and his abrasive temper are examples. Still a genius though, and less of a copy-cat and technology thief than the later Edison.

  14. The US ordnance folks spent a lot of time monkeying with the HS404 design, ie; AN-M1, M2, M3, and M-24, with varying degrees of success. The Brits used a slightly different chamber dimension and had much better results. This spec was shared with US ordnance, who chose to ignore it and tinkered instead with the mechanics.

    • The big problem was the conversion from metric to inch. The American conversion ratio was off and affected all of the parts measurements. The British also measure parts like the bore differently, so their aid wouldn’t necessarily help.

  15. It would made an interesting armament for an early tank. Bursts of 37mm automatic cannon may have been more effective than single shots from a six pounder. The 37mm gun also would have been much lighter than the six pounder.
    I’d have put the Maxims aboard the Whippet light tanks. This would have given the “lights” the ability to reduce fortified villages, as well as enabling them
    to suppress the German mobile anti-tank guns.

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