Guppy
Bearcat
Clean the striker and striker channel in the slide. Then look for machining flaws or metal burrs / chips that may be impeding that striker. Once done with that check the function fo the firing pin block (the round button on the inside of the slide). While you have the stiker out remove the mag safety to eliminate it as a cause. See the FAQ's at the top of the forum for more info on how to do these things.
