The Chichizola MPA: Argentina’s full-auto pistols, Part 2

In 1977, the urge of “firepower, compact style” showed up again at Fábrica Militar de Armas Portátiles “Domingo Matheu”, one more time as an in-house private venture. Designer Enrique Chichizola started studying technical approaches to an automatic-fire gun of small dimensions capable of achieving such stability and controllability characteristics so as to allow effective target hit probability at realistic ranges (say, up to 10 meters). He called it the MPA (Mini Pistola Ammetralladora, Mini Machine Pistol).

Cut-away drawing of Enrique Chichizola’s MPA with an 18-round magazine in place. Note the well-inclined configuration of the pistol grip.

Cut-away drawing of Enrique Chichizola’s MPA with an 18-round magazine in place. Note the well-inclined configuration of the pistol grip.

His approach could well be called “ergomechanic”, since a deeper interface between firer and machine was involved. It basically consisted of aligning the gun barrel’s axis as much as possible with the firing hand’s supporting point with views at reducing the respective force momenta (during firing) of the gun’s center of gravity and the shooter’s hand/arm. This resulted in the adoption of a specially designed pistol grip that was just about an extension of the receiver’s rear end, with a generally conventional trigger/trigger guard assembly just ahead of it. Chichizola had, in fact, considered other more unconventional solutions, one of these being the replacement of the trigger proper by a thumb-activated lever on the receiver’s side, not to mention what he considered to be the ideal answer: a sort of spade grip at the very rear end of the receiver! This, in the event, was not even tried, as it might have appeared too revolutionary for the FMAP management, who could politely have asked the designer to stop… designing.

What was left of the first MPA on top of a 1:1 scale drawing of the pistol. The long 40-round magazine sketched was apparently used for photographic purposes, only.

What was left of the first MPA on top of a 1:1 scale drawing of the pistol. The long 40-round magazine sketched was apparently used for photographic purposes, only.

Well, the MPA was otherwise a rather conventional blowback affair firing 9x19mm ammo out of a 105mm long barrel that sat pretty low in the boxlike receiver. A very high cyclic rate of fire (1,500 to 2,000 rounds per minute) was intended to take advantage of the principle that that in a rapid and short (3 to 4 rounds) burst, by the time the firing momentum starts rising the muzzle, the bullets are already in their way to the target. So, a lightweight (320 grams) bolt was used, whose guide rod and stiff return spring were in the upper position. At the breech-closing moment, the bolt would be well forward in the receiver, ahead most of the barrel’s length, thus giving a definite downward push at the muzzle end. Ejection was to the right.

The right side view of the Chichizola prototype main body (18-round magazine in place) shows the small ejection port and the pressed-steel cocking piece on the forward top of the receiver.

The right side view of the Chichizola prototype main body (18-round magazine in place) shows the small ejection port and the pressed-steel cocking piece on the forward top of the receiver.

The gun used staggered-row, two-position feed, metal box magazines of 18- and 25-round capacities, an even a 40-round unit was occasionally fitted (apparently, for photographic purposes, only). The catch release button was located just ahead of the magazine well, being pressed inwards (left to right) to release the magazine. It was located within the disassembly pin which allowed the upper and lower receiver assemblies to come apart. The cocking piece was a pressed-steel structure of pretty low profile involving the top of the receiver.

An internal publicity photo showing the MPA prototype a with a 40-round magazine, alongside the 9x19mm FMK.3 submachine gun that was series produced (estimated 30,000 examples) for several years at FMAP “Domingo Matheu”, in Rosario, Santa Fé Province.

An internal publicity photo showing the MPA prototype a with a 40-round magazine, alongside a 9x19mm FMK.3 submachine gun that was series produced (estimated 30,000 examples) for several years at FMAP “Domingo Matheu”, in Rosario, Santa Fé Province.

A single prototype was put together in Rosario and proved its point well. Although a controlled burst device was actually built, it was never fitted into the MPA, magazines loaded with four rounds only simulating it for testing purposes. Chichizola told me, years later, that single-handed shooting at man-sized silhouettes at 12 meters – that is, well over the close-in ranges anticipated for that sort of firearm — generally resulted in the four bullets impacting in the kill zone, which appeared to confirm that muzzle raise was very modest, indeed.

However, and unfortunately, the full-auto pistol prototype did not receive further (or any, in fact) support from Army guys outside the factory gates, and the whole testing program slowly came to an end.





Ronaldo Olive

Ronaldo is a long-time (starting in the 1960s) Brazilian writer on aviation, military, LE, and gun subjects, with articles published in local and international (UK, Switzerland, and U.S.) periodicals. His vast experience has made him a frequent guest lecturer and instructor in Brazil’s armed and police forces.


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  • roguetechie

    Thanks Renaldo,

    I very much appreciate the pictures etc they’re immensely helpful to me.

  • BattleshipGrey

    Too bad it didn’t get fully run through its paces. I can hear the collective gasp of the Glock “grip angle” complainers now though.

  • Well, that looks cool as heck. There’d be a definite market for a semiauto version.

    • roguetechie

      Texas,

      Do you really think so?

      I’m actually building something inspired by this, but using a mix of existing parts that are heavily repurposed.

      I’ve also added a series of pretty cool features to it.

      I was just designing and building it as a fun gun… One of those pieces you pull out at the range and everyone stops to say wazzat!!??

      Some of the feature sets I’m working should give it beneficial usability characteristics as well as allowing a “carry mag” version to ride concealed Carry style if you’re so inclined.

      When I’m finished I could probably talk Nathaniel into posting a writeup here about it….

      Here’s the big question though:

      Would you buy a kit version and be willing to assemble it yourself?

      If so, this could likely help fund my 02/07 LOL

      • jamezb

        I’m not scared of a bit of fitting…

        • roguetechie

          I’m very seriously thinking about doing it.

          OK question 2:
          What caliber (s) do you think people would prefer?

          I ask because my first few will be in a caliber that would be a tough sell for most people.

          I’m leaning towards 9mm just for simplicity sake and ready magazine availability.

          That said, if I start making the initial kits and sell enough of them you can expect caliber conversions and other stuff above and beyond that to also be offered.

  • Giolli Joker

    I like it… unconventional, low bore axis and it seems perfect to complement a sawed off shotgun on the side of a Mad Max style hero.

  • JoshCalle

    Love it, love everything about it, from the whole mad max chopper aesthetic to the stupid pirate pistol grip angle, I need it in my life.

  • Jonathan Ferguson

    Fascinating Ronaldo, thank you. The flintlock-style grip angle as a means to control recoil is very interesting. I could see it working particularly if there was a fire grip to pull down on also.

  • Ggtexas

    Looks like something out of warhammer 40k

  • AD

    I like it! I wonder if it would be possible to build something similar, but using a more exotic magazine (I’m thinking something like the FN P90 or the Calico) to make it easier to fit in a pistol-style holster?

    • Avery

      Funny you mention that but one of the versions of a 5.7x28mm pistol was a “pirate pistol” version of the P90. I doubt it was ever built, but it at least developed a patent under the number USD377077 “Pistol”. It even featured a forward-mounted charger, which also doubled as a thumb stop. Not much is known about it, since nothing of it exists but illustrations, but I think it was fitted with a shortened P90 magazine that held 20-25 rounds.