Firearms having a locked breech are disclosed. An example firearm includes a barrel; a bolt head; a firing pin having a bulge; a bolt head carrier having a forward position and a rearward position; a central force receiving component receiving a rear end of the barrel and defining a plurality of recesses; and a locking bolt penetrating the bolt head. The locking bolt is movable between: (1) a locked position wherein the locking bolt engages in the recesses of the central force receiving component to thereby lock the bolt head to the central force receiving component and (2) an unlocked position wherein the bolt head is free to move with the bolt head carrier. The locking bolt is pressed by the bolt head carrier into the locked position when the bolt head carrier is in the distal position. The locking bolt defines an oblong hole which is penetrated by the firing pin. The oblong hole has a beveled edge which engages the bulge of the firing pin to push the firing pin rearward when the locking bolt moves from the locked position to the unlocked position. The barrel defines a gas intake opening. A gas cylinder is located in the central force receiving component. The gas cylinder is in communication with the gas intake opening. The bolt head carrier forms at least a portion of a gas piston which cooperates with the gas cylinder.