The SPAs: Argentina’s full-auto pistols, Part 1

Like most countries that manufacture guns, Argentina has also done its share of research trying to come out with a decent (light, compact, accurate, controllable) full-auto pistol. The whole thing started at the Government-owned Fábrica Militar de Armas Portátiles “Domingo Matheu”, in Rosario, Santa Fe Province, in 1974 as an in-house effort. Being an established licensed manufacturer of the FN Browning Hi-Power, the factory found it proper to use it as the basis for what was called the SPA (Sub Pistola Ametralladora, Sub Machine Pistol).

The single 7.63x21mm Mannlicher SPA prototype built, slide to the rear, is seen here with the 16-, 25- and 40-round magazines.

The single 7.63x21mm Mannlicher SPA prototype built, slide to the rear, is seen here with the 16-, 25- and 40-round magazines.

Since the Hi-Power’s usual 9x19mm cartridge was recognized as too-much powerful for a hand-held, full-auto, very-high-rate-of-fire gun, the guys down South decided to use a somewhat milder cartridge, but still capable of producing serious wounds on humans. They chose the 7.63x21mm Mannlicher cartridge for long (1905-1916) used in the Argentine Army Austrian-made Steyr-Mannlicher Model 1905 delayed-blowback semi-auto pistols. With an 85-grain bullet coming out of the gun’s 160mm barrel at 312 m/s, the ammo had been locally-produced in vast numbers for years and the tooling had been retained for eventual manufacture re-entering.

The 7.63x21mm Mannlicher SPA prototype fitted with a 25-round magazine, which protruded about 30mm from the bottom of the pistol grip.

The 7.63x21mm Mannlicher SPA prototype fitted with a 25-round magazine, which protruded about 30mm from the bottom of the pistol grip.

The resulting SPA involved only twelve new or modified parts, the most evident being the 159mm long barrel which protruded about 40mm from the slide, with 16-, 25-, and 40-round magazines being made for the single prototype built. The cyclic rate of fire was in the region of 1,000 rounds per minute. The fire selector was a button located immediately above the trigger: pushed from right to left, the pistol fired full auto; from left to right, semi auto.

The SPA with the 40-round magazine in place. About 40mm of the 159mm-long barrel extended beyond the slide.

The SPA with the 40-round magazine in place. About 40mm of the 159mm-long barrel extended beyond the slide.

The Army high-brass, however, later provided funding for five prototypes chambered for 9x19mm, but the resulting guns were untamed beasts. I had a chance to briefly fire one of these in a visit to “Domingo Matheu” in February 1990, and can summarize the SPA performance as “BRRRR… an empty magazine… and three or four hits on a man-sized silhouette at three or so meters away!” That’s probably why the SPA project was shelved a short time after it started.


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.


  • Tim

    Full auto (minus 3-round burst) on anything but a crew served weapon is essentially a novelty.

    • AC97

      And what would a three round burst accomplish?

      What about close range?

      • ostiariusalpha

        Close range with a 3-round burst should be fine, you don’t have to be Jerry Micelek to quickly bring the muzzle back on target and hit them with another burst. Three to the torso, and then three again, is better than four on target, two over the shoulder, and six towards the sky. Even if you keep them all on target, that’s only good for eliminating one threat, which is not all that great of a protection strategy.

        • AC97

          In my opinion, I think replacing the full auto position with a three round burst position is kinda stupid, as the M16A2 did, as I believe that it’s better to have versatility and train them to use short bursts. The military seems to agree with that idea, as in the M4A1.

          You thought that I meant for general usage, as opposed to referring to a mechanical limitation, didn’t you?

          • ostiariusalpha

            Well, we’re talking pistols here, rifles are a whole other deal that burst fire doesn’t do much of anything beneficial for. There is no training that will make a 9mm handgun controllable on full auto, you end up having to slow the rate of fire down to where it’s actually less immediately disabling then what the burst can do at a thousand RPM.

          • AC97

            Oh, well I made the mistake of thinking about full auto in general. I’m sure that’s something I need to work on in general, thinking someone’s generalizing and all.

            I wonder if two round bursts would be a good option for machine pistols…

          • ostiariusalpha

            No, entirely my fault, Tim was generalizing, and your response was appropriate. As for 2-round burst, I’d increase the rate of fire up to around 1500 RPM, which would make for very effective controllability with fast wounding. Seems like you have a very good idea there.

          • Anon. E Maus

            I think it’s very much different.
            The M16 is a gas operated rifle that has an average rate of fire, it has three points of contact (stock, pistol grip, fore end), controlling an M16 in full-auto is a cakewalk and burst fire is really pointless here.

            But consider a machinepistol, most are short-recoil, and this one here has exactly one point of contact, the grip.
            It has no stock or foregrip, thus bore-axis makes itself very known with a weapon like this, especially given that it cycles at 1000rpm. Besides being just hard to control, it’s very easy to hold on to the trigger for longer than you meant to, so you can easily fire more rounds than necessary. If it had a three round burst instead, it would fire up to three rounds and then stop, allowing you to retain control and pull the trigger again. It allows for better control, better accuracy, and better use of ammo.

            Fundamentally, it’s just easier to control a rifle on full-auto than it is a pistol, this is why it’s different, this is why burst seems like a better idea to me on a machinepistol than on a rifle.

  • MrFN

    Stocks and foregrips, everyone. Stocks and foregrips.

  • Anonymoose

    If we could reduce the rate of fire and it had a ported barrel the 9mm might be more controllable.

    • demophilus

      One might also try different 9mm loads, or analogs. 6.5 CBJ has the same form factor as 9mm, as do 9mm THV and “Cyclone” (tubular bullets). The law of conservation of momentum still holds, but different weights and launch velocities could provide more options for mechanical recoil mitigation.

      One idea that hasn’t been tried is a traveling charge propellant — they have been demonstrated in tank/APC guns, but not small arms. A traveling charge combusts as it moves down the barrel, not just at the breech, so it would provide a different, more attenuated pressure spike. A combustible sabot or hollow base (like on a THV) in 9mm could host a traveling charge. But it’s still a lot of work to get to something with a limited tactical niche.

      A full auto 9mm can be done, but there are good reasons nobody’s gone whole hog at it. Other, less complicated weapons still do most of the same jobs better and cheaper.

  • Edeco

    I like this idea, i.e. going with a heavy-ish tactical/practical size gun and a sub-9mm cartridge. To me the ideal would be a long slide CZ75 or Jericho 941, 6.5″ hose, steel frame so a fore grip can be firmly attached, chambered in like a warmed up 7.63×22 French Lounge-pistol… like in the 90-grain, 300 ft. lb. range. Highly ventilated slide. Would have to be way more controllable than a G18.

    Any point to doing so? Martial shooting isn’t my department, but look at it this way, it would be a perfect kitten in semi-auto mode, and then one would also have the option of ludicrous output.