A firearm comprises a frame and firing control housing insert detachably mounted in the frame. A rear securement feature includes a locking slot formed in the rear wall of the insert engaging a locking protrusion formed in the rear wall of the frame which retains the rear portion of the insert in the frame. A front securement feature includes a rotatable pin inserted through holes in the insert front portion and frame. A radial retention protrusion on the pin is interposed between the insert and frame defining an interlock feature. The pin is rotatable into a first position wherein the protrusion passes through a complementary configured frame aperture allowing the pin to be removed, and a second position wherein the protrusion is not aligned with the aperture to engage the frame and prevent pin removal.

A firing control system for a firearm includes a frame, a barrel with chamber configured for holding a cartridge, a spring-biased striker movable forward and rearward in a linear path along a longitudinal axis, a trigger mechanism comprising a trigger, a pivotable sear, a pivotable sear connector engaged with the sear, a sear pivotable connector blocker engaged with the sear connector, and a linearly movable sear connector actuator engageable with and operable to move the sear connector and sear connector blocker. Pulling the trigger slides the sear connector actuator which in sequence engages and rotates the sear connector blocker to disengage the sear connector, and engage and rotate the sear connector to disengage the sear and release the striker from a cocked position to discharge the firearm. In the absence of a trigger pull, the sear connector blocker remains engaged with the sear connector to prevent firing the firearm.

A hydraulically dampened rotary barrel locking system for a handgun is provided which preferably includes a receiver, a barrel and a spring-loaded moveable slide. The barrel comprises one or more axially aligned locking lugs configured to allow the slide to travel down the barrel axis when the lugs align with a keyway slot in an extended lug boss at the discharge end of the slide. Felt recoil is reduced and accuracy is improved due to a more balanced slide-to-barrel mass ratio than prior art and hydraulic dampening between the barrel and slide due to improved journal bearing action.

A hydraulically dampened rotary barrel locking system for a handgun is provided which preferably includes a receiver, a barrel and a spring-loaded moveable slide. The barrel comprises one or more axially aligned locking lugs configured to allow the slide to travel down the barrel axis when the lugs align with a keyway slot in an extended lug boss at the discharge end of the slide. Felt recoil is reduced and accuracy is improved due to a more balanced slide-to-barrel mass ratio than prior art and hydraulic dampening between the barrel and slide due to improved journal bearing action.