Shooting the MAS-38 Submachine Gun: Second Try

Take 2! I have some ammunition loaded up for me by awesome viewer Cameron, and we’re going to try it out in the MAS-38 submachine gun. This is loaded hot enough to properly cycle Mle 1935 pistols, unlike the ammunition available form Reed’s and Buffalo Arms. However, it is a bit shorter than the original French loading, and I don’t know if the length and bullet profile will properly cycle the MAS-38.


  1. You should now send a letter to BATFE requesting NFRTR be modified to reflect this weapons status as single shot only (on a good day), as there is clearly no way to make this MAS 38 fire full auto.

    • Fat chance of getting them to do that! A paranoid person might suspect you will swap out parts (including the barrel), get the thing to fire 9×19 military grade ammunition, and then go out on some rampage to mow down random crowds of people in cold blood! Believe me, lots of bureaucrats in my neighborhood are stupid enough to think that the yard tools in any random tool shed can magically turn aluminum cans (and nothing more than that) into assault rifles capable of sawing the White House in half just by glaring at it (without even firing once). They don’t even think about ammunition and assume the lead just magically comes from nowhere… I wonder how they graduated from preschool.

  2. The power of passion s clearly visible. Unfortunately, by itself not enough. Tech,lots of tech is needed to get it working. Someone should convince Prvi Partizan to make this round.

    • “Tech,lots of tech is needed to get it working.”
      Oh, when you write that I for some reason start to think about percussive maintenance, but sadly it would not help in this case.

  3. Golly, that is a twee little bullet sprayer! I hope that it gets up and running soon.
    I guess the ammo is so hard to find that the prices of iffy surplus would be impossible to actually shoot.

    Hopefully some company will produce a run of it, although the market outside the U.S. might be really small indeed. In the U.S., I’ve seen the pistols both “As” and “Ss” periodically, so I would think it would be somewhat more available. If I had vast sums of capital, say a thriving .45 SAA company I could mortgage to the concept, I’d make a run of Pedersen devices designed to operate in Mosin-Nagant rifles of recent import with the magazine floor plate and follower removed. It couldn’t possibly be as bad a decision as the “Zip .22” or whatever that thing was called reviewed here not too long ago… “Make the gun and the ammo will follow” or something like that.

  4. I don’t know if you read this, Ian, hopefully you do, because I can promise you, you’re nearly there.

    The failure to fire there was seemingly an obvious head spacing issue. Does that round chamber off the case mouth? Shoulder, rim, or o-give?

    Seat the bullet (projectile) out farther and/or leave the brass trimmed long. It will work. I promise.

    Your cartridge is falling into the chamber about .010 farther than I would spec the cartridge to.

    Also, check your firing pin for shortening. I’ve seen them run short over time.

    Last, consider your barrel is more worn and has a deeper “MG” chamber, as found on many Tokarev 7.62×25 variants, chamber and cartridge. My pistols were all more forgiving with out of spec ammo, vs a subgun.

    • If that’s the problem, the answer isn’t fiddling with the ammunition. It’s to bore out the chamber to about 0.5″ diameter and 0.9″ long, silver-solder in a 1.00″ long steel blank bored to 0.3095″, then run a 7.65 Long chambering reamer into it to re-establish correct headspace. There will be roughly 0.12″ freebore, but that shouldn’t matter.

      Although from what I’ve seen of MAS 38s generally, there seems to be a fundamental problem with them working at all. I suspect the angled movement of the bolt causes binding; a similar problem afflicted the early model Jati-Matic SMG in the 1980s.

      The French Army were probably correct in developing an entirely new SMG, the MAT 49, after V-E Day. And the French police may have been less well-armed with the MAS 38 up to the 1960s than they thought.



      • “MAS 38”
        I want to one that cartridge case for that weapon was originally made from steel, bullet jacket also was made from steel, according to Альбом конструкций патронов стрелкового оружия data bullet jacket material is “steel; hardness 190 Vickers”.
        Its cartridge is named as 7,65-mm cartridge for sub-machine guns which imply data are for that weapon, velocity is given as 380 m/s at distance of 10 m from muzzle with 5,5 g heavy bullet. Material used for cases might have influence on functioning of blow-back weapon.

        “French Army were probably correct in developing an entirely new SMG, the MAT 49”
        In fact they were already developing other sub-machine gun before Fall Gelb. Namely Pistolet Mitrailleur Modèle 1939 PETTER and Pistolet Mitrailleur Type ETVS basic data see:
        50 of each are said to be delivered, though I do not know if they were supposed as replacement for MAS 38 and if yes what they considered as bad trait in MAS 38, this might, but do not have to be reliability, they might for example consider it too expensive.

  5. Ian:
    Have you looked to see if you can get some info from the French on the exact case dimensions,and bullet shape?

    Also see if you can get the exact dimensions of the firing pin? Along with the firing pin depth? You’re getting some firings, but the pin might be a little worn out after 70 or so years, and your bolt spring too, not enough forward momentum to really wack the primer. And the gun may be needed to run really wet lubricated. Just a few ideas that you overlooked.

  6. I visited France in around 1980 and remember seeing cops with MAS 38s.

    I lived in Paris briefly in 1990, and recall cops with MAT49s, and model 36 rifles. And probably MAS38s. But can’t be sure.

    I can’t believe the French kept the 38 in service for 50 years if it fundamentally did not work. Not shot one, but have the feeling that a working one would be rather nice, excepting the wound ballistics.

    As I understand it, the French plan pre-1939 was to issue the MAS as a PDW to second-line units, but procure a 9mm SMG for the infantry. The latter did not emerge, so the MAS (and Thompson) was hurriedly fielded as an infantry weapon upon invasion.

    The idea of issuing two SMGs to different army branches, in different calibres, as well as rifles, is obviously questionable. Ie stupid.

    Hopefully, Ian, your book on French guns will show how distinctive the French were with small arms – they seem to have covered the bases all the way from “great idea” to “mad”.

    • Well, of course the US Army did pretty much the same thing with the M1 Carbine and its unique cartridge. Like the .30 Carbine for a semi-auto gun, the 7.65 Long makes a lot of sense for a full auto PDW. The recoil is very manageable, but the ballistics are still good enough for an effective range of about 100 meters.

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