After the removal of the APS from the armament of army units, it was used in special services units. In 1993, by order of the Ministry of Internal Affairs, an attempt was made to modernize the APS. The modified pistol was planned to replace the 5, 45-mm and 7, 62-mm Kalashnikov assault rifles, which are dangerous in urban conditions. But, for a number of reasons, this work stopped at the very beginning. At the end of the same year, the Ministry of Internal Affairs concludes an agreement with the Tula TsKIBSOO for the development of a new automatic pistol chambered for 5, 45 MPTs. The theme entrusted to the team under the leadership of Igor Yakovlevich Stechkin, and then the pistol, was named "Dart".
The low power and weak stopping effect of the 5, 45-mm cartridge significantly limited the scope of the new weapon. Already in July 1995 the OTs-23 "Dart" pistol is planned to be modified under the 9x19 "Parabellum" cartridge. The new development interested the Ministry of Internal Affairs, and by the end of the same year TsKIBSOO received an order for the development of a 9-mm automatic pistol, but chambered for the domestic 9x18 PM cartridge in standard and reinforced versions. In April 1996, the first sample of a 9-mm automatic pistol was manufactured, which was named OTs-ZZ "Pernach", and in July 2002 it was presented at an international exhibition in Moscow.
"Pernach" inherited from "Dart" the original scheme of automatic operation: to reduce the impact of recoil on the accuracy of automatic firing (with a free shutter scheme), both pistols have a movable barrel. In the OTs-ZZ, after the shot, the bolt rolls back 70 mm and hits the massive spring-loaded barrel, with which it continues to move for another 5 mm. Due to the shock attachment of the mass of the barrel to the mass of the bolt, the speed of the latter is significantly reduced. Upon reaching the rearmost position, the barrel and bolt, under the influence of their springs, begin to move forward. After 5 mm, the barrel stops, and the bolt continues to move and sends the next cartridge from the two-row magazine to the chamber.
In comparison, both pistols have a double-action trigger mechanism. The included fuse reliably locks the firing pin, bolt, hammer and trigger, providing complete safety when handling a loaded pistol, and the fuse can be turned on both when the hammer is released or when the trigger is cocked. By the way, the fuse also serves as a fire translator. For shooting from both hands, safety flags and magazine latch are made symmetrically. The indicator of the presence of a cartridge in the chamber is noticeable visually and to the touch. The rear sight and front sight are equipped with inserts to facilitate aiming at dusk.
To reduce the "toss" when firing "Pernach" has a gas compensator. When the bullet passes in the bore, the powder gases enter the cavity of the shutter-casing and are reflected upward. However, this simple and effective device has disadvantages: it not only led to the increase in the length of the pistol, but also makes it difficult to shoot from positions where the weapon is located close to the shooter, for example, when shooting from the hip. In addition, when an object, say, a spent cartridge case, enters the compensator cavity, a delay occurs.
But with all the external similarity, "Pernach" is qualitatively different from "Dart", and not only in caliber. A cartridge of 9 mm caliber with a higher stopping effect of a bullet made it possible to abandon the concept of accumulating damage due to a quick triple hit on the target. The OTs-ZZ lacks a three-shot burst cut-off mechanism, and the rate of fire has been reduced from 1800 to 850 rounds per minute. To increase stability when firing, the more powerful Pernach received a removable stock (the OTs-23 lacked a stock in the TTZ), but due to its short length, such a stock is only suitable for dwarfs. If necessary, a laser designator and a device for silent and flameless can be installed on the pistol.
