In some guns this can cause the gun to fire out of battery resulting in a case separation. Watch for wear on the recoil spring. With time, the sides of the spring will wear flat, weakening the spring. This is usually visible to the naked eye. Don't try to remove all slack when adjusting the trigger.
Some slack is required for the trigger bar to reset between shots.
Likewise, do not take all of the over-travel out of the trigger. This will allow the sear to drag the hammer as it falls, shortening it's life. Dry fire only with a plastic plug in the chamber. Be careful of the rear sight mounting screw. It has a large head, but the screw is very small and can be twisted off if tightened too aggressively.