The first variant was introduced, in limited number, at the end of the '60s for the Italian Navy special forces and is easily recognizable from the longer barrel, about one inch, and the presence of a birdcage-type flash suppressor. It has been replaced by the
Heckler & Koch MP5. The Model 12 was redesigned as the
Beretta Model 12S in 1978. The Model 12S uses a 32-round box magazine, and is chambered for the 9×19mm
NATO cartridge. A novel feature is the
grip safety, which locks the trigger and the bolt in the closed position, thus safeguarding against accidental firing if the grip is not held firmly or if the gun is dropped. The safety and fire-selector switch, which in the original Model 12 were two separate push-pin button (with the fire-selector being a button that activated single-fire or burst fire whether it was pushed on the right side or the left side) have been re-engineered in a modern lever-type selector with three positions (S for "Sicura" or Safety, 1 for Single-fire, R for "Raffica" or Burst fire). The fixed firing pin on the face of the bolt can strike the primer only when the cartridge is chambered fully, and this also avoids accidental firing, according to its designers. The PM12S was also designed with easy field-stripping and reassembly in mind, which has been simplified and can be accomplished without tools. It can be equipped with a
suppressor, but this requires a slight modification of the barrel by a competent
gunsmith. Minus the suppressor and other optional features, the Beretta PM12S is made up of 84 discrete components. The current version of the Beretta Model 12, is called the
PM12-S2. In the mid-1980s the Italian Carabinieri, after a misfire accident, asked for a modification, in the form of a further safety device, which allowed both to keep the bolt of the weapon in half-cocked position and acted as an interceptor preventing accidental fire should the bolt or the firing pin suddenly disengage. This modification was implemented as a standard factory feature, and the denomination of the submachine gun changed to
PM12-S2; this is the only Model 12 variant currently manufactured by Beretta. ==Users==