When I got my P-3AT the Parkerized finish on the slide was perfect. After shooting 100 flawless rounds I now see some brass colored scratching on the top behind the ejection port as seen in the picture. I tried to clean it off with some regular Hoppes cleaner, but it did not come off. I was thinking this could be from the shell getting hitting the top of the slide on the way out. Has anyone else seen this before, and should I worry about it? Is there another cleaner that would get it off, or should it go back to the mother ship do to a finish flaw?