 The rollers then come into contact with inclined surfaces on the locking piece and propel it backwards at a speed that is approximately 1.5x greater than that of the bolt head, thereby increasing the bolt's inertia and providing a delay in the blowback sequence.The relatively short initial rear displacement of the bolt head immediately after firing and the calculated delay eliminate the probability of a premature case extraction from the chamber (beyond the thick-walled base of the chamber) that would result in the spent casing bursting as the breech is opened only after the bullet has exited the barrel and gas pressures inside the bore have dropped to within safe limits.The Ameli fires from an open bolt and uses a striker firing mechanism (in which the bolt and internally channeled firing pin perform the role of a striker).