A firearm includes a frame and a slide. A firing mechanism for the firearm
includes a striker-type firing pin, a trigger, and a trigger bar. A sear
inside the frame is pivotally balanced about a central fulcrum, and is
biased in a first pivotal direction by a spring. In this position, a rear
portion of the sear engages the firing pin. Actuation of the trigger
causes the trigger bar to move rearwards for engagement of a forward
portion of the sear. This pivots the sear in a second pivotal direction,
against the spring, which releases the firing pin. The spring then causes
the sear to pivot back for reengaging the firing pin when it returns to
its rear position. Movement of the slide to a retired position causes the
trigger bar to disengage from the sear (preventing discharge of the
firearm) until the slide returns to a battery position.