US Patent 8985005 Repeating firearm

A mechanism for a repeating firearm has a body pivotably mounted within the receiver and movable between a first position where it blocks motion of the bolt carrier, and a second position where it engages either the trigger or the hammer to prevent discharge. In operation the body is moved from the first position to the second to release the bolt carrier, which moves into battery. The body is then allowed to move out of the second position toward the first position. The rife may be discharged by a pull of the trigger, and the bolt carrier moves out of battery and is arrested by the body before moving back to battery. If the body is maintained in the second position during operation its engagement with the trigger or hammer prevents discharge of the firearm.