I just purchased a Glock 19 about a month ago and I have probably put around 400 or 500 rounds through it. I last shot it about a week and a half ago and cleaned it immediately after using it. I didn't notice anything when I cleaned it and put it in my gun safe, but tonight I got it out and got ready to go to the range and noticed some strange parallel markings on both the top and bottom of the barrel. The marks look like if you connected them, they would go all the way around the barrel, but they are only on the top and bottom, only on the outside, nothing on the indide. The markings look like wear on the coating on the barrel, not scratches. Is this kind of wear normal after this few rounds? Just to be safe, I decided to skip the range until I can get some more info on what's going on. By the way, I'm a Glock newbie, and a new gun owner to boot, so if this is a dumb question, please forgive my inexperience. Any help is greatly appreciated. Thanks!