TZ-45

The TZ-45 was an Italian submachine gun produced in small numbers between 1944 and 1945, with an estimated 6,000 made.
History.
The TZ-45 submachine guns was designed by two Italians, Tonon ("Toni") a colonel in the RSI Army and Zorzoli a gunsmith, and was produced by the Giandoso company. All the TZ 45's were issued to R.S.I. (Repubblica Sociale Italiana) units fighting against Italian partisan forces during the civil war in Northern Italy (1944–45), yet it is possible that a few of them ended up serving with Wehrmacht forces engaged in similar operations. After the war, the remaining guns were given to the military of the British and the American forces. It was then evaluated by them, but the general opinion was unfavorable. The gun emerged from the war with a poor reputation for reliability and the style of manufacture and finish was unpopular.
The projects and manufacturing rights for the gun were later sold to the Burmese army where it was manufactured as the BA-52 and colloquially known as the "Ne Win STEN". The Burmese copies were roughly manufactured and unreliable, but they remained in service into the mid-1980s with their infantry and even into the early 1990s with support troops.
Development.
Compared to the FNAB-43, the TZ-45 is much more the sort of weapon one would expect in that place and at that time. It was made out of metal stampings, welded together in parts, and the finish is rudimentary. For all that, it worked and managed to exhibit one or two interesting features. The action is simple blowback, but the return spring is assembled around a guide rod which is in two pieces and telescopes as the bolt returns. A muzzle compensator is fitted, and the shoulder stock is formed of steel rods that slide alongside the receiver when retracted. Two separate safety systems are fitted: the fire selector lever has a “safe” position that locks the bolt in either the forward or rearward positions, while a grip safety is fitted behind the magazine housing. Unless the weapon is held properly and this grip compressed, the bolt cannot move in either direction to cock or fire. Even with a closed bolt and a magazine inserted, the pin of the second safe wedged in a specially-designed notch in the lower center-left part of the bolt, preventing the bolt itself from rolling back in case of accidental shocks taken by the weapon. Considering that accidental discharges were an all too common occurrence in contemporary submachine guns (Sten gun and others), the double safety system of the TZ-45 proved to be a breakthrough which would inspire many later submachine guns, starting from the Danish Madsen M50.