You can look on either side of your lower, the pins I’m talking about hold the trigger and the hammer in place and, at least on my 10.5" PSA KS47, tend to walk out of one side or the other. The trigger and hammer continue to function, but the hammer seemed drag and started to produce light strikes. All I had to do was lineup the hole and simply push the pin back in place. If this does turn out to be the issue for you, they make anti-walk pins that are easily installed.