 This method of operation also allows the use of standard and higher power 9x18mm ammunition without using a locked breech action.To further reduce felt recoil and compensate for muzzle rise during firing, some propellant gases are diverted into a ported slide cavity that acts as a muzzle brake and compensator, deflecting the gases upward to stabilize the barrel.The OTs-33 has a double-action trigger mechanism and is hammer fired, with an exposed hammer.