See if you can find even a fellow shooter who has a bore scope. That can reveal issues that looking down the bore from the end does not. I've also had the experience of having a Springfield barrel that looked unrusted but that actually turned out to have pitting that had been glazed over by carbon until it looked like rifling. Wet the chamber and bore with Gunzilla and let it sit for a month then patch it out and see if anything like that has been loosened up. If you want to go faster, plug the muzzle with a Neoprene stopper and fill the thing with Slip 2000 Carbon Killer and let it sit for three or four hours, then drain it back into the can or into a secondary container (it's still good at that point) and patch and brush it out. The only caution I have is that this stuff will mark Parkerizing when it's on it this long, so don't let it sit on the finish. The Gunzilla won't hurt anything. It's just slow with aged, hardened carbon.
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