After several thousand rounds through my PPQ 9mm, the trigger has become very "gritty". I clean and lube after every shoot, and detail strip/clean the slide every 500 to 1000 rounds). I've read older posts, and all seem to focus on the striker safety plunger. I'm guessing this is not the cause in my pistol, because the trigger is still very gritty with the slide removed. However, when I apply slight pressure against the trigger bar (pushing it away from the frame), the take-up is glass smooth. Could this indicate a problem with either the trigger bar, or the adjustable trigger bar guide (I seem to remember reading that somewhere, a while back)? Any input would be greatly appreciated. THANKS!