I have a .40 px4 that I have only fired about 500 rounds through. I was cleaning the gun tonight and noticed a lot of wear on the bottom of the chamber end of the barrel. I hadn't noticed this before and was curious if anyone else that might have this gun has had this problem. A new barrel would cost me roughly $300 and figure that it may be to my advantage to sell the gun and buy something different. Any suggestions, or is this common in other guns too?