The FNAB-43 SMG is a delayed blowback operated, 3.9 kg, selective fire, submachine gun that was used by Italy during World War II.
It used the 9x19mm Parabellum Cartridge and it was about 79 cm long with the stock exended. It could be retracted, however, and the new length would be 52.6 cm. It could either have a 20 round box magazine or a 40 round magazine and the rate of fire was 400 rounds per minute.
The unique 2 piece bolt is enclosed and there is also a lever that is enclosed near the bolt pieces; this lever is set to delay the starting movement of the mechanism. Another unique feature of the FNAB is the muzzle break and the compensator. The foldable stock is designed so that troops can maneuver the weapon more easily.
For iron sights, the FNAB had a V-shaped rear sight. The FNAB was also almost entirely made of steel. The FNAB was produced from 1943 to 1944 and only 6,000-7,000 of them were made. Compared to other submachine guns, this is extremely low and this might of have been caused by the time consuming process to make a FNAB.
However, production was also hindered by the fact that Italy surrendered only a year after production ended. In field tests, the FNAB was a very efficient and reliable weapon which contradicted the Italian production movement of mass-producing weapons, which meant cutting costs.
The FNAB was used by Italian and German forces, mainly those stationed in Northern Italy in defensive positions in order to stop the allied advance. Despite low production, the FNAB proved very effective. This little known submachine gun never became the standard Italian submachine gun, however which led to its rarely known status.