Yesterday I was at the range doing type 3 malfunction (double feed) drills with my G17. During the drill, there were a few times I put spent 9mm casings in the chamber instead of complete bullets. This was recommended to me by someone who worked at the range. I had 2 times where my gun got really jammed. I think in these cases the casings had bulges and didn't want to come out. I had to have the RO clear the jams. I don't remember exactly what he did, but he had to whack the back of the slide pretty hard to clear the jams. Afterwards he said not to put spent casings in the barrel. Otherwise, I could mess up my barrel and extractor.
When I got home I looked at the rear side of the barrel where the feed ramp is. I saw some scratching and bumps that I hadn't noticed before at the 11 o'clock position on the feedramp and on the face of the barrel at the 7 o'clock position. I'm not sure if this is a problem or if it is related to what happened at the range. My G17 has around 7,000 rounds through it.
I'm wondering if I may have damaged the barrel and, if so, should I do anything to correct it? Here's a picture of the barrel. Note I soaked the barrel in ballistol a few hours and then cleaned it before taking this picture.
Any advice is appreciated.