I recently purchased a new model ten Savage 308. The rifle seems to be very accurate in early tests but I noticed scratched cases on extraction. So far, breaking in the rifle I've only fired jacketed bullets mostly factory odds and ends I had on hand. I took a look with my endascope (sp) and there seems to be a streak of some sort that looks like solder or lead streak on the 8 o'clock portion of the chamber and it doesn't clean out with my AR-10 chamber brush no matter how much I scrub. Any ideas what this may be and possible at home fix. Thanks Gp