Mendoza 1934: Mexico’s Domestic LMG

Rafael Mendoza was Mexico’s premier domestic arms designer, and the Model 1934 LMG is probably his most successful design. He began work on it in 1929, and it entered testing with the Mexican Army in 1932. It was formally accepted by the Mexican Army in 1934 (hence the designation) and would serve into the mid 1950s. Mendoza was a private civilian, but production of the gun took place in the state-owned National Arms Factory in Mexico City, with Mendoza himself receiving no royalty or licensing fees. Instead, his company was given a contract to make the magazines for the guns.

Mechanically speaking, the Mendoza 1934 is a gas-operated, rotating bolt, magazine-fed LMG chambered for 7mm Mauser (the standard Mexican military cartridge at that time). Production actually began in 1939, and would continue into the 1950s with about 5,000 made in total. The main purchaser was the Mexican military, but some were also exported to Guatemala, Costa Rica, and Cuba (both Batista and Castro). With he end of World War Two, there was a huge glut of American surplus arms, and Mexico adopted the BAR and the Browning 1919, which replaced the Mendoza in Mexican front line service.

If you are interested in more details about the Mendoza 1934 or any of Rafael Mendoza’s other designs, I highly recommend Luis Eduardo Gonzales’ book on Mendoza, available in English in both print and Kindle versions:

Many thanks to the Royal Museum of the Armed Forces and Military History in Brussels for access to this very rare piece! Check them out here:


  1. !Oy-caramba!

    under that promising slick narrow profile receiver is hiding a design nonsense which is THREE rows of locking lugs (maybe influenced by Mondragon?). Did senor Mendoza get to see Lewis up close? He could have jus copy it, or even better Mexican government to buy the license.

    To match three sets of lugs with three sets of recesses simultaneously is a mission close to impossible unless an extremely tight tolerance is used. Look what Russians did with the same idea in DP-27 a couple of years earlier, a much better take.

    But the magazine is my main point of contention. One wants to sob in despair when looking at this contraption. Better to have a shot of tequila. Other than that good show by Ian; much appreciated.

    • “(…)magazine(…)”
      How magazine works is described in detail in even thought it is titled MACHINE GUN BOLT MECHANISM. One of aims of designer seems to be attain hold-open (This arrangement is provided so that the bolt will not be released from firing position by the operator when the shells are exhausted from the magazine and gun keeping the bolt in cocked position ready to actuate on the introduction of another magazine filled with shells)

    • It seems like a prototype put in production before all the elements had been figured out throughly.
      Very good and simple operating mechanism, barrel change mechanism, general ergonomy, controls, gas settings… But three sets of lugs? That bipod (I’ve seen better in WWI)… no handle to grab a scorching hot barrel… And that magazine…
      It could have easily been so MUCH better.

  2. Mendoza also made a neat little falling-block .22 LR action, pistol & rifle, that was locked by the hammer fall. Simpler & easier to make than a STEN, just a delight in minimalist engineering.

    • I would agree with term “minimalist” if it was not for those three rows of lugs. But I appreciate the man’s work; he wanted his country to have an indigenous machinegun. He was a military officer as I understand so this was kind of kick out of the boredom.

  3. Mexico has done some interesting things with firearms. The FX-05 Xiuhcoatl is a good example, and one I’d love to see Ian highlight. Don’t ask me how, other than by walking up to some Mexican Army soldier and asking, but… It’d be interesting to see the internals on one of those, and get Ian’s impression of how well it shoots.

      • That guy fumbles; he does not know what he is doing. I hate when I see people fuss with guns; they do not belong even close to them.

    • Heckler Koch had years ago some legal hokey-pokey with Mexican government over their “snakie” rifle. The former accused the latter with forgery of G36. At the end they settled for no-fault; case dismissed. Mexicans originally wanted to buy a license, but later declined – they obviously figured how to go around it. For those who do not know, Mexican students at universities are studying from English worldwide textbooks; they are not to be underestimated.

      I have seen video of manufacture of their rifle in domestic facility. You would not believe it – the workers are members of Exercito Mexicano and the are dressed it fatigues. No kidding.

      But then you say to yourself – this is Mexico, a different place altogether. I visited there once at the end of 1983 and saw it on my own eyes; in busy tourist town group of soldiers were patrolling with rifles and inserted magazines. Happy holidays!

  4. Also… I’d be willing to argue that this is actually a “direct impingement” weapon, by some definitions of that term. No piston, the gas is directed into a cup at the front of the operating rod, and for all intents and purposes, this is about the same as a Ljungman or MAT49/56, just upside down with an operating rod extension.

    Just sayin’…

  5. Carramba, indeed!
    A Lewis op-rod coupled with Hotchkiss gas mechanism with HK mechanical ejector…

  6. Reminds me a bit of the top-feed light rifle/ M1 carbine entrant/prototype by John Cantius Garand. Similar influence from the Lewis Gun, and with a top-mounted magazine feeding from the upper right of the receiver, ejecting out of the left side.

    Garand’s prototype top-feed light rifle for Springfield Armory had the magazine canted about 45 degrees to the right like the Pedersen device magazine, and yet the sights were offset to the left. Mendoza’s machinegun is remarkable in that the sights are centered, I suppose. I agree that the magazines look wonky and trouble prone.

  7. We should have replaced the Bar with Mendoza. The quick change barrel put the 1934 light years ahead of the Browning. Too bad that the Ordnance Department was asleep at the switch during much of the Thirties.

    • According to
      Developed from Mendoza’s earlier M1934 light machine gun, the RM-2 was originally produced for a US Army contract in the mid-1940s. However, when World War II ended in September 1945, the Americans rescinded the contract before it could be fulfilled. Since Mexican laws prevented the weapon from being exported, Mendoza had little choice but to market the RM-2 domestically. It was trialed by both the Mexican Army and the Mexican Marine Corps, but both rejected it. Ultimately only 50 prototypes were ever produced.

      • That is surprising – the RM-2 was quite a bit more developed and in right caliber. No Mexican ground troops were involved with war in Europe (they were fighting in Philippines as an expeditionary air-force unit); they would have great difficulty with ammo supplies.

        • Had Mexico contributed ground forces to WWII instead of the vast reserve army of labor for U.S. industry and agriculture, etc., and the squadron of P-47s flying close air support missions in the Philippine archipelago, it would very likely have resembled the FEBianos of Brazil: Brazil contributed an infantry division and some air assets to the Italian Theater. All of the small arms were .30-06, .45 acp, .30 M1 carbine, etc. from the suite of U.S.-produced weapons, mostly M1903 Springfield rifles, but some Garands.

  8. I suppose nobody here has read Thomas Pynchon’s enormous novel “Gravity’s Rainbow,” set in 1945-46. The British Commando “Pirate” Prentiss arms himself with a Mendoza, thought it’s non-standard and “nobody’s even seen any 7mm Mexican Mauser rounds lately …” Pynchon goes on to describe the good points from Prentiss’s point of view. It was years before I found out the gun was genuine — thought the author had made it up. His details on the V2 rocket were all correct too.

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