I just put around 60 rounds through a new Glock 19 Gen 4 and when I went to clean it afterwards I discovered a spot on one of the forward metal guides in the frame. This gun is brand new and under the rough spot a copper looking surface has been revealed underneath. It looks like there may have been a stainless coating on top of that piece. It is rough to the touch and I don't know whether to take it back to where it was purchased or what to do at this point. I am attaching a picture of the area below.