Italian submachine guns were born from the original Fiat-Revelli Modello 1915 "Villar-Perosa" weapon of 1915 which saw service in World War 1 (1914-1918). This marked the first deployment of a "submachine gun" type weapon in any warzone but the product was hardly a useful form with its unorthodox twin-barrel design. It initially found issuance to Italian alpine troops and was typically utilized in the light machine gun role as opposed to the shock-assault role against enemy infantry. A late-war entry, the Beretta Model 1918, brought the gun more in line with traditional submachine gun thinking by encasing the metal components of the Villar-Perosa gun (with just one barrel) into a service rifle stock. A Beretta trigger unit was mated to this and the Italians had a serviceable submachine gun on their hands.
From this work begat a newer line of submachine guns to emerge from Beretta prior to World War 2 (1939-1945) - the chief product becoming the "Model 38A". The submachine gun was chambered for the ubiquitous German 9x19mm Parabellum pistol cartridge firing through a simple blowback system of operation. The type went on to see formal acceptance in the Italian Army (and elsewhere) and proved an excellently made, very durable battlefield system - remaining in circulation throughout all of World War 2 with production not ending until the 1950s. Its use went beyond that of Italy's during the war for the Germans and Romanians were both known to field the weapon in useful numbers during the conflict.
The Model 38A was a departure from the original Villar-Perosa roots and formed more of a Beretta-centric end-product. The rifle-style stock was retained with its integrated shoulder section, pistol grip handle and forward handguard under the barrel. The trigger group was underslung under the frame in the usual way with a magazine feed situated well-ahead of this area. Sighting was through a rear and forward assembly aiding ranged fire. The barrel was encased in a perforated jacket for inherent air cooling properties. Of note was the weapon's unique "double trigger" unit which showcased a pair of trigger assemblies - the forward installation allowing for instantaneous semi-automatic fire while the rear-set trigger allowed for quick access to full-automatic fire - the decision left up to the operator without the need to fumble with a selector lever. A muzzle compensator aided in combating "barrel climb" to an extent. For the purposes of close combat, provisions for a front-mounted bayonet were featured in early production batches - a rare quality for a submachine gun considering their intended short-to-medium range usage on the battlefield but the World War 1 trench warfare mentality was still there heading into World War 2.
The weapon showcased an overall length of 37.5 inches with a barrel measuring 12.5 inches long. Unloaded weight was in the 4.20kg range. The weapon could feed form a 10-, 20-, 30-, or even 40-round detachable box magazine with a cyclic rate-of-fire of 600 rounds-per-minute. Muzzle velocity was listed at 1,370 feet per second.
Well-made, these submachine guns suffered through what most interwar period designs suffered from - they were quality weapons which made them heavy to wield and expensive to produce. This had the beneficial effect of making the weapon very robust under the abuses of wartime service which was always a well-liked quality in any service weapon for infantry. Expensive, time-consuming machined steel was used early on during manufacture.
Once World War 2 had involved Italy, the Model 38A was already in widespread circulation and became the standard submachine gun of Italian Army troops. However, its expensive nature quickly led to refinements of the system by 1941 in which the muzzle compensator and bayonet support were dropped and sheet steel was incorporated into manufacture. At about this time, a new 9mm cartridge emerged as the "9mm Cartuccia Pallottola Modello 38A" which promised an increase in outgoing velocity. In response, the sights of the gun were regraduated to make up for the newfound power.
Despite the attempts at alleviating Model 38A submachine gun production costs, the line was largely revamped with the introduction of the wartime Model 38/42 of 1942. This form lost the barrel jacket common to the original model and used sheet steel in its receiver manufacture process from the get-go. Several other changes were brought into the design to make for a more cost-friendly end-product. The Model 38/43 and Model 38/44 were continuations of the original Beretta Model 1938A line while the Model 38/49 became a post-war variant.