Argentina’s 9x19mm FMK 3 submachine gun

    Following WWII, Argentina’s State-owned FMAP-DM (Fábrica Militar de Armas Portátiles – Domingo Matheu), located in the city of Rosario, Santa Fé Province (380km Northwest of Buenos Aires), carried out production of the .45ACP caliber Colt M1911A1 pistol (about 70,000 examples), and the 7.65x53mm Mauser M1909 cavalry carbine (20,000) for Argentine Army use, having used primarily machines and tools acquired from the German firm Fritz Werner. Also, under the direct supervision of three Italian designers from the city of Brescia – Bergonzi, Ruggieri and Sustercic – the Factory designed and manufactured about 50,000 examples of the P.A.M.1 and P.A.M.2 submachine guns, 9x19mm weapons based largely on the U.S. .45ACP caliber M3A1 ‘Grease Gun’ (

    This was the losing entry to the late-1960s FMAP-DM in-house competition for an indigenous “pistola ametralladora”, the name of its designer remaining unknown. Looks like the magazine-in-pistol-grip configuration was a basic requirement.

    In the late 1960s, the Product Engineering Department of FMAP-DM started work on a number of tentative 9x19mm projects aimed at selecting a winning indigenous design for series manufacture. The model eventually chosen was the creation of designer Magin Almará, and was initially designated PA 3 DM, from the Spanish language initials of Pistola Ammetralladora (Machine Pistol), 3rd Model and the factory’s name. Weapons of the early production batch of about 4,500 units were known as P.A. (0202) FMK 4 Modificación 1 (solid plastic stock) and P.A. (003) FMK 3 Modificación 2 (retractable wire stock), but were finally defined, respectively, as the FMK 4 and FMK 3, only. Well, so much for designations!

    This rare surviving picture (regrettably, slightly cropped on top) shows the very first PA 3 DM prototype of Magin Almará that evolved to the FMK 3 and FMK 4 subguns. Note wooden stock and handguard, plus the 25-rd magazine.

    Total production in the 1970-1980 period reached the 50,000 mark, the weapon being subsequently placed in widespread use with the local armed and police forces, with some exports having been reported. In 1982, a redesigned, more-stylish model was proposed, but never placed in production.  A semi-auto-only variant, the FMK 5 (locally called “Subfusil Semiautomático”), was also produced and locally sold on a limited basis for private security use.

    The FMK 4, fitted with a rigid plastic stock, is actually 10mm longer than the FMK 3 with the wire stock extended, but weights are the same. This variant, however, was built in substantially smaller numbers.

    One’s first glance at the conventional open-bolt, blowback-operated FMK 3 will immediately confirm that the gun was conceived with low-cost, mass-production in mind. In a black enamel finish, it is widely built of stamped sheet-metal pressings, the handguard being the only plastic component you’ll find in the weapon. The rectangular lower receiver includes an integral pistol grip (which doubles as magazine housing) and accomodates all the trigger/firing mechanism assemblies, as well as the external guide tubes for the retractable wire stock. The upper receiver, a cylindrical job, obviously houses the barrel and bolt assemblies, incorporating the sight units on top. The two receivers are held together by two spring-loaded pins which are removed from the weapon sideways for field disassembly.

    An FMK 3 is seen here fitted with a locally-made sound suppressor, which about doubles the gun’s length.

    A wrap-around bolt is employed, so that about 180mm of the 290mm long barrel (six grooves, RH twist, 1:250mm pitch) are enclosed within it. This type of bolt is somewhat more expensive to manufacture, but is generally credited with making the weapon more stable in firing, mainly in full-auto (cyclic rate of fire: 600-650 rounds per minute), and reducing the overall length without sacrificing ballistic efficiency. In this particular aspect, however, the Argentine subgun is still a comparatively long piece at 690mm with the wire stock in the extended position (520mm, fully retracted). The gun’s weight with a fully-loaded 40-round magazine is 4.3kg, while its empty weight is a respectable 3.8kg, as much as any decent assault rifle around! A 25-round magazine is also available, both versions being of the staggered-row, two-position feed type.

    An exploded view drawing of the FMK 3 and 4, the sole difference between them being the type of stock fitted.

    The magazine fits into the stamped metal grip, which by necessity is located at a 90-degree angle relative to the gun’s longitudinal axis. This arrangement perforce leaves something to be desired in the ergonometric department and the so-called instinctive pointability. Although there’s no way escaping from a ‘fat’ grip to accommodate the magazine, the one fitted to the FMK 3 is particularly uncomfortable, particularly to small-handed fellows like yours truly. And to make things worse, there’s a lousy grip safety lever (which I dislike, in principle) on the squared back of the pistol grip. If not fully pressed inwards by the shooter’s palm (in a somewhat unnatural hold) the bolt will remain locked in either the closed or open position, so as to avoid accidental discharges due to mishandling or drops of the weapon.

    Author about to insert a fresh 40-round magazine into the FMK 3 during firings conducted at a range of FMAP-DM in Rosario, sometime in the early 1990s. The gun looks bulky, but indeed it is!

    The magazine catch is conveniently located at the lower rear end of the pistol grip, being pressed inwards to  release the mag and allowing an easy one-hand operation. The button-type charging lever is situated on the left side of the receiver, just above the plastic handguard, and does not reciprocate when the gun is fired. A slot cover helps in keeping dirt away from the weapon’s inside. The fire selector, a lever on the left side of the lower receiver, halfway above and between the trigger and pistol grip, has three positions: “S” (Seguro, Safe), top; “R” (Repetición, Semi-auto, center); and “A” (Automático, Auto), bottom. Although it was certainly designed for actuation with the thumb of the right (firing) hand, my experience with the gun has shown that this is not naturally achieved as a result of the thick pistol grip. However, I’ve found it perfectly okay flipping it up and down with the thumb of the left (supporting) hand.

    Being comparatively heavy (4.3kg with a full 40-round magazine) and possessing a moderate cyclic rate of fire (600-650 rounds per minute), the FMK was ease to fire and control at full-auto, even in the informal fashion shown in photo, wire stock retracted.

    The wire stock appears to have come straight from a WWII-vintage ‘Grease Gun’, its sole advantage being the ease of manufacture and low cost. Other than that, it is rather uncomfortable and flimsy. To extend the stock, press a latch on the rear side of the receiver and pull the piece rearwards, a two-handed operation for the average user.

    The three positions (S-R-A) of the fire selector lever are clearly seen in photo, as is the grip safety lever.

    The hooded front sight is a post adjustable for elevation, while the aperture rear sight, L-shaped and adjustable for windage, has usual and realistic settings for 50 and 100 meters, sight radius being a generous 320mm. All my firing experiences with the FMK 3 date back to the early 1990s at an outdoor range at FMAP-DM, and I just can recall they were “average, acceptable, okay”, nothing particularly “outstanding”, nor “compromising” in any way. I do remember to have liked the existing combination of the FMK 3’s slow rate of fire with its heavy weight, with gave it an “A” grade in full-auto stability and controllability.

    The breech area is seen here with the bolt at the rear, ready to fire. Note the two-position feed offered by the magazine and the general dimensions of the ejection port.

    Equally, the gun showed simple, no-fuss take-down/assembly procedures requiring no tools. All in all, the FMKs do not symbolize any sort of technological breakthrough or creativity in the firearms field. However, they do represent a more than justified effort of a developing country in becoming self-sufficient in the small arms field by creating and producing in an industrial scale its own SMG. That this was achieved should be a reason of pride.

    Sometime in the early 1980s, the FMAP-DM design staff considered giving the FMK a slightly more stylish appearance, this involving the handguard and pistol grip shapes, only. However, not a single example was completed in this fashion.

    The FMK 3 general design simplicity resulted in equally simple field-stripping procedures. The wrap-around bolt, however, required a more elaborate manufacturing process.

    Some FMK 3s in the hands of Uruguayan Army soldiers, known users of the gun. Peru and Bolivia are other reported users (Photo via Oyoy Kanamox)

    An Argentine female police officer with her FMK 3. (Photo via Oyoy Kanamox)

    This particular FMK 3 has been fitted with a studier tubular metal stock. Operator appears to be an Argentine police officer. (Photo via Oyoy Kanamox)

    An extensively modified, semi-auto FMK 5 reportedly seized from criminal hands in Argentina some years ago. (Photo via Oyoy Kanamox)

    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.