 The new pistol has a "square" shape, which is simpler (and less expensive) to manufacture and has a novel operating principle that increases controllability and reduces recoil.The OTs-33 is a selective fire blowback-operated weapon firing the 9×18mm Makarov pistol cartridge; it can use both types of 9x18mm ammunition, the standard 57-N-181S and the more powerful 57-N-181SM round.The blowback operation incorporates a feature that separates the slide and barrel as they move to the rear during recoil; there is no positive lock between the slide and barrel as in other conventional designs.