Halcón M - 1943 The Halcón M - 1943 is a submachine gun of Argentine origin and is chambered in both 9x19mm Parabellum for the Army and . 45 ACP for police forces . This weapon is comparable in quality and performance with the Thompson submachine gun . Development . In the 1950s , the FMAP DM ( Fábrica Militar de Armas Portables Domingo Matheu ) , belonging to the Dirección General de Fabricaciones Militares , acquired the production rights of a copy of the U . S . M3 A1 submachine gun , more commonly known as the " Grease Gun " . This Argentine version was chambered for 9x19 mm cartridges , as opposed to the . 45 ACP in the original model . The DGFM released two versions called PAM 1 and PAM 2 , with and without handle latch . In the early 1970s , FMAP DM decided to change the design using the forward - mass , evolving closing system and a charger in the grip . . This charger was designed by Jaroslav Holecek in mid - 1946 and greatly reduced the size of the weapon . He popularized the CZ - 23 / 25 and it was later also adopted by the Israeli UZI , the Ingram MAC - 10 and the Star Z - 84 . Thus was born the PA - 3 DM , later known as the FMK - 3 . At first glance , the FMK - 3 may be associated with the UZI . This Argentine sub - machine gun fires the 9x19 mm Parabellum cartridge and hosts its charger on the handle , which in turn carries fire and security systems . Above the hand grip , appears a receiver which houses the locking system and recoil spring . In the first series , the FMK was presented with three versions of stocks : one - piece plastic fixed , fixed to wood , and retractable wire . On the left side of the upper receiver the lever is to carry and assemble the closure in late position . This lever consists of a sliding dust cover that prevents the entry of foreign materials in the interior of the weapon . On the same side but at the rear is the belt holder . In early versions , the front one is similar to the Uzi , although it went on to be captive and rotating in the shield that holds the barrel to the receiver . On the receiver aiming devices are : a dash protected by a tunnel and a rear sight adjustable booklet orthoptics laterally and with 50 and 100 meters height positions . It is all protected by side ears . The ejection window is discretely sized and is located to the right of the aforementioned drawer or upper receiver . Unlike other similar submachine guns , the guarantor , the disconnect and auto insurance the FMK - 3 are located behind the handle . In this way , ahead of the trigger queue is only the selector mechanism of shot and the manual safety . This insurance has a wing - type command that is activated from the left and which presents three positions : upper intermediate , " S " ( safe ) , " R " ( repeat ) , and " A " ( automatic fire ) . As an additional measure of security , the FMK - 3 has a secure grip that acts in the following way : If the weapon is not correctly grasped , the safety locks the sliding of the closing . Thus , even if the gun is ready to fire , if not pressed , handle insurance trip system remains blocked . In addition , as mentioned above , with the closure at rest , empty chamber and the full magazine a lock that prevents accidental fall of the weapon drag a cartridge there is an unintentional shooting occurs . Therefore it is a very safe weapon to carry in any condition . In short , it ' s a simple , reliable and pleasant weapon to use , may sometimes seem outdated compared to other more complex and expensive weapons . However , this Argentine piece remains a safe option when choosing a good weapon . Variants . M - 1943 . The Halcón M - 1943 came with a fixed stock protruding from its grip section . M - 1946 . The Halcón M - 1946 came with an underfolding stock . Later variants came with sidefolding stocks .