The FNAB-43 is an Italian designed and developed submachine gun manufactured from 1943 to 1945. The first prototype was built in 1942 and the ~1,000 built by the FNA-B according to Ian McCollum of Forgotten Weapons were issued to German and Italian RSI units fighting in Northern Italy. The FNAB-43 was an expensive weapon to manufacture as it used extensive milling and precision engineering in its manufacture.