The first sub-machine guns appeared towards the end of World War I. The light two-barrelled Viliar Perosa machine gun was the forerunner of the submachine gun, inasmuch as it was the first to use pistol-power ammunition. But, whereas the Viliar Perosa was not by definition an assault weapon-although fitted with a sling, its great weight impaired its speed and efficiency-the sub-machine gun, as it had developed by the end of the war, had all the lightness and handiness that made it the new weapon par excellence fora ssa ultdetachments.
The Italian sub-machine gun at the end of World War I, the M1918, was a direct descendant of the Viliar Perosa. It had been developed by using one barrel of the Revelli machine gun fitted to a rifle stock. The necessary alterations to the new weapon were made by Tullio Marengoni, an engineer from the Beretta armoury at Gardone Valtrompia. This sub-machine gun, although not officially adopted by the Italian Army, was the first of a series that Beretta supplied and still supplies to Italy's armed forces.
The next model of the Beretta was the M. A.B. 1918-30, a selective fire weapon which, like its predecessor, used the 9-mm Glisenti cartridge. It is still used today by Italian forest rangers. In 1935 another model was issued, which was fully automatic and which, modified slightly by Tullio Marengoni, led to the creation of the prototype for the 1938 model. The new sub-machine gun was in 9-mm Parabellum calibre: it had two triggers, the rear one for firing bursts, the other for firing single shots: the barrel could be fitted with lugs on which a bayonet with a folding blade could be fixed.
A few minor alterations, such as the addition of a four-slotted compensator, and variations in the line of the stock, resulted in the M38A, for which Beretta had an immediate order. The first 500 of these sub-machine guns were sent to arm the Italian colonial police in Africa. These, like a large number of their successors, had a fixed bayonet tfiat could be folded back along the barrel.
The Beretta M38A sub-machine gun was a 9-mm calibre weapon, chambered for the Fiocchi M1938 cartridge, which is so similar to the 9-mm Parabellum that the two cartridges are interchangeable, although the former is rather less powerful than the latter. It worked on the blowback principle, with a fixed barrel: only the breechlock recoils, under the pressure of the gas on firing, ejecting the spent cartridge case, recocking the firing pin, and loading a fresh round into the chamber. It also had two triggers. It was 37.25 inches long (barrel 12.4 inches), and weighed 9.25 pounds. Magazines of 10, 20, 30 or 40 rounds could be used, and it had a rear sight calibrated to 300 metres. The protective barrel-jacket had small circular holes cut in it for cooling.
The next model, the Beretta M38/42 (or more precisely 1943), differed from the M38A on several points: the barrel was shortened to 8.4 inches; the barrel-jacket was removed; it could have a single sight calibrated to 100 metres, or a blade rearsight calibrated on 200 metres; it weighed 7.2 pounds, (the M38/43 weighed 7 pounds); and measured 31.5 inches long. In this weapon the muzzle velocity of the bullet was 1,250 feet per second (it was 1,378 f. p.s. in the preceding model).
The production of the various models of M. A.B. was delayed at the beginning of World War II, and therefore the first were ready only in 1942, when they were distributed to special detachments. After September 8, 1943 a few of the M. A.B. s that had been kept in the arsenals were taken to arm partisan troops, while the greater number were requisitioned by the German occupation troops.
World History
