My PF9 failed to ignite four rounds, trigger cycled but did not fire, racked that round out and another one in, again trigger cycled but did not fire. This happened four times until I had ejected the last round from the mag. Loaded the same mag from the same box of ammo (Federal) and all rounds fired perfectly. Don't know what gives but I'm shaken, don't know if I can trust the weapon. I do carry it, or used too. Any ideas?