A firearm having a hammer and a bolt mechanism capable of recoil movement behind the hammer, so that the bolt assembly in recoil momentarily clears the hammer. A timing lever senses rearward travel of the bolt assembly and prevents the hammer from release, irrespective of trigger mechanism operation, while the bolt assembly is momentarily behind the hammer. The hammer timing lever is engaged by the forwardly-moving bolt assembly to release the hammer and return control of the hammer to the trigger mechanism.