I picked up a GP100 about a month or so ago. I’ve noticed a lot of what appears to be heavy copper fouling just past the forcing cone, and there’s a spot inside the bore that is stubborn as heck. I’m wondering if the spot in the bore isn’t rust (although I doubt it is). The cylinder chambers had a good amount of copper fouling in them as well which seemed to respond well to boretech copper solvent and some elbow grease. I’m wondering if this gun wasn’t fired a bit at the gun shop that it came from. It was a gun broker purchase so not a local shop. I’ve attached some pictures and would appreciate any and every input I can get on this. It’s driving me nuts, but I’m not sure if I should even let it get to me or not. The gun does its job and shoots great and accurately. It’s become my new EDC. I just have a pet peeve for keeping my weapons squeaky clean.