Systema OBREGON: The Mexican Rotating-Barrel 1911

This is Lot 1500 in the upcoming October Morphy Extraordinary auction.

Patented by Alejandro Obregon in Mexico in 1934 and in the US in 1938, this pistol is an adaptation of the classic Browning 1911 to use a rotating barrel locking system. In addition, Obregon integrated a couple other clever elements. The safety lever and bolt stop were combined into a single part, in the process doing away with the need for the plunger tube on the side of the frame. The mainspring was made into a contain unit with the guide rod and spring plug, and a magazine safety was added through slight modification of the trigger bow and magazine catch.

Only about 800 of these pistols were made, at the Fabrica de Armas factory in Mexico City. It was not adopted by the Mexican military (which used the M1911A1), and was relegated to private sales only.


  1. Whether or not the rotating barrel is an improvement over John C. Browning’s design, the one-piece safety lever and hold-open definitely seems to be a better idea.

    • John M. Browning wisely placed the safety where your thumb naturally finds it, sweeps it down in a comfortable motion, and rests on top until you make a conscious choice to reposition your thumb and reapply the safety.

      It’s not clear from the video, but it would seem like resting your thumb there would disable the beneficial hold-open on an empty magazine function; and that trying to correct for this by putting your thumb underneath could have the (even worse) effect of inadvertently safing (and locking open) the Obregon at an inopportune time.

      I’m all for simplifying / reducing parts count, as long as this doesn’t cause a loss of necessary functionality. One could omit the detents, spring, and tube on a 1911 too, if not concerned about the levers positively clicking into each position. I believe the best compromise is using stamped lever(s) with stamped dimples that click into matching divots in the frame.

      • I don’t think Browning ever considered 1911’s safety to be a thumb rest. It became like that only when competitive shooting and two-handed grips became a thing, to have a lower bore axis. In historical one-handed stances the thumb is alwais under the safety lever, otherwise you are not gripping the gun securely.

        • I don’t see resting one’s thumb on the safety as an obstacle to a secure one-handed grip (I don’t have a 1911 in front of me, but it certainly isn’t a problem on my P365), but I’m perfectly willing to believe that the high-thumb hold wasn’t popular in the pre-“gas pedal” days.

          A low hold wasn’t a problem on the 1911 because of its positive detent stops. I just re-watched the video, and saw no indications that the Obregon lever has anything but gravity holding it in the down / disengaged position.

          • There is an audible “click” when Ian engages and disengages the safety, and no sign of the lever moving if it’s not moved by force.

          • Looking at the video I notice 2 things, 1) there is a shelf on the safety cutout on the slide and a corresponding lip on the back of the safet/slidestop (@ about 4:46). The “clicks” heard were probably the sound of the lips running over the shelf. Best guess is that the body of the stop/safety lever acts as a flatspring to resist going over the shelf.

          • I posit that the recoil spring end plug, impinging on the slide-stop/safety’s shaft through the locking block, is holding it in the down position. In Ruby pistols this arrangement is used to fix the safety in either position, and indeed, to keep it in the gun.

      • I’ve never used the 1911 safety for a thumb rest! I’ve ground off thumb rests like on the Colt Woodsman grip. In fact, I prefer the European “down is on, up is off” safety position.

        • The Obregon magazine safety looks easy to override if you need to: simply depress the magazine release while pressing the trigger.
          It’s funny the same style of magazine safety is present on current Browning 1911-22 pistols (the 85% size .22 LR 1911 look-a-like ).

    • “(…)Whether or not the rotating barrel is an improvement over(…)Browning’s design(…)”
      I think it would be interesting to compare it to Star A Super:
      which was also derived from 1911 and featured different locking system.
      In theory non-tilting barrel should enhance accuracy, however I do not think it would have big impact on practical accuracy, as in case of automatic pistol generally accuracy is limit by human abilities, rather than automatic pistol (excluding extremely worn or very poor made examples). I am wondering how it does compare to 1911 in terms of service life, that is average of how many shots might be fired before need of refurbishment?

      • A rotating barrel is not inherently more accurate than s tilting one. It has the advantage of allowing you to use a simpler barrel shroud (I mean the part of the slide that touches the front part of the barrel. Disadvantage is that the tilting barrel helps a bit in loading a bullet, and the rotating one does not.

  2. “(…)Alejandro Obregon in Mexico(…)”
    Do we know anything about him, beyond his action in field of fire-arms designing.
    I heard that name earlier… let me think… General Álvaro Obregón become president of Mexico in 1920. This is probably just coincidence, but if there was, but if not that would be interesting relation

  3. The rotating barrel pistols are perceived as more demanding from manufacturing standpoint (as example, pre WWII war vz.24 pistol was not easy neither cheap to make) but they offer a benefit in better control. Interestingly, the biggest and last purveyor of this design, Beretta has dropped it form their production. Glock has recently introduced a pistol in this configuration for police use, but number produced is apparently low which makes it even more peculiar.

    Also note one interesting detail as how action unlocks/locks. Some are counter-clockwise (as is Obregon) and some are clockwise turned in order to unlock and I am not sure if there is a practical significance to it. On superficial observation one would tend to think that counter-clockwise (LH) direction of unlock is opposing to RH direction of rifling and may add to resistance of rotation, however barrel itself may be spun into opposite direction as a natural reaction to projectile’s motion. In other words, it is not a clear cut.

    • It doesn’t seem to me that Beretta ceased the production of the PX4. There had been rumors of it updating the design instead.

      • Right, PX4 is still part of offer at least in U.S.

        Apparently I was influenced by cessation of model which was replaced by PX4 – the Cougar

        New model has plastic grip, both have fire control done by hammer. Their locking is rationalised in sense that barrel includes cam (cuts for either side made by end-mill while barred is rotated in chuck)while actuating stud is part of grip assembly. This seems to be most economical arrangement for rotary barrel pistols to date.

      • For a very simple to manufacture rotating barrel design, I’ll take the MAB PA-15, (that’s a delayed-blowback, and not breechlock rotating barrel design). The design is simpler than a Browning tilting-barrel, and the finishing is even crude for a western-made service gun of the ’60s.
        It’s true that the rotating-barrel delayed-blowback design seems to be a recoil-enhanceer, but to turn that design in a breechlock one is only a question of inclination of the single locking surface.

    • Talking of the vz.24,it seems to me that Mr. Obregon studied that design very well.
      Unfortunately, after having had a brilliant idea about the breechlock, the Czechs decided to concentrate on that design all the possible defects. Made for a cartridge that didn’t need any breechlock, high bore axis for a .380, a grip angle that screams “uncomfortable”…

      • Czech service .380 shot was an extra-hot version of it. It could be fired by straight blowback but just barely. The grip angle is definitely not right; they should have looked around a bit.

        • According to Ezell in Handguns of the World, the Vz.24 design was originally intended to be made in 9 x 19mm, so it would definitely have needed the locking mechanism. The Czech government decided on production in 9 x 17SR basically on economy grounds.

          Note that the later Vz.27 kept the basic layout of the Vz.24, but was a straight blowback in 7.65 x 17SR.



          • “(…)9 x 17SR(…)”
            9mm vz. 22 (alias: 9 mm náboj pro pistoli vz. 22) is rimless.
            It launched bullet 6,0 g at 300 m/s – same mass as 9×17 Kurz, but faster than default loading of second encountered in 1930s Europe.

  4. Obregon, Star, Ballester-Molina. After-Browning tinkerings/improvements, and even Star had one in 11.43mm.
    A comparison shoot or even a group review would be nifty.

  5. 1) And in the current rotating-barrel sweepstakes, let us not forget that fine product of Slovenia, the Grand Power, a 15-shot 9×19 DA/SA polymer-framed service type pistol. Not well known here or Mr. M would surely have mentioned it.

    2) I would think the phrase, “rotating barrel replacing Browning’s tilting bolt” a little awkward when remembering Browning patented his own rotating-barrel pistol back in 1898, as seen in an earlier post on this site. (I still don’t know how Roth-Krinka-Sauer-Steyr didn’t get sued for their 1900 and 1907 guns.) Maybe “applying Browning’s lapsed-patent rotating barrel in place of his tilting barrel” might be more appropriate.

    • Sorry, read “tiling barrel” for “tilting bolt.” That Colt-Browning 1895 machine gun video was just too recent.

    • 1900 and 1907 Kyrinka pistols were “Rotating Bolt” types, not “Rotating Barrel”… First rotating barrel production pistol was “Steyr 1910” which having very complicated take down and first practical rotating barrel model was Joseph Nickl’s Vz22 that its take down are copied by the most of current same type locked breech pistols excepting GP100. IMHO…

      • “(…)sued for their 1900 and 1907 guns.(…)”
        I would say reason is much more simple, but firstly: K. Krnka (not to be confused with S. Krnka [also fire-arms designer], not to be confused with “Krinka” and definitely not to be confused with “Kyrinka” [whoever he or she is]). Ad rem:
        K. Krnka was working in Austria-Hungary, then Austria and finally Czechoslovakia:
        In years 1900 and 1907 in Austria-Hungary and (at least back then) U.S. Patents were U.S. Patents and patents of European countries were patents of European countries, therefore if J.M.Browning did not have patent in proper country, patent infringement was not possible at all.
        (Case from later history: Poland in 1930s adopted ciężki karabin maszynowy wz. 30 which might be called blatant knock-off of Browning recoil-operated machine gun, however Fabrique Nationale not patented it in Poland, so it was perfectly legal move)

    • LDC… The Grand Power is a Slovakian product, not Slovenian. Slovakia is a nation formed from the bits of slightly more Slavic, somewhat less Germanic Czechoslovakia. Slovenia, on the other hand, was the sane bit of Yugoslavia, and the part that was, oddly enough, more Germanic.

      Easy mistake to make–Lots of people do it, to the point where the Postal Union people from both countries get together periodically to swap mail that’s been mis-addressed.

      Slovenia did not get much of the former Yugoslav weapons plants, but they did get enough to be able to form Arex. There’s also Polenar Tactical, which is an amusing bunch of gun nuts I’m surprised haven’t hooked up with Ian already. They have to know where some interesting stuff is buried, in Slovenia… Maybe even literally.

    • “let us not forget that fine product of Slovenia”

      Err, not Slovenia, Slovakia. Slovenia is couple hundred kilometers south and west.

  6. The Colt All American 2000 designed by Gene Stoner and Reed Knight was promising but Colt was failed its industrialization process.

  7. We should not forget the recently introduced Glock 46 in 9×19 with its rotating barrel design, chosen to be able to handle even hotter than +P+ police and military loads.

  8. I have always liked the Obregon design, but I am surprised that only 800 were made.

    My copy of “Military Small Arms of the 20th Century” by Ian Hogg and John Weeks says it was in production from the mid 40s to the mid 50s. It is hard to believe that production averaged a mere 80 a year.

    Of course, Mexico has strict gun control, which must hamper legitimate civilian sales. On the other hand, no-one in Mexico who wants a gun seems to have any trouble finding one.

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