Well I still don't know what was up with the black bore, but I went after the copper with Montana Extreme Copper Killer and it got out quite a bit more than the Pro Shot Copper Remover. It was still black after cleaning, but felt way smoother when finishing up. I then loaded up about fifteen 6.5x47 rounds with some oddball bullets I only had a handful of (100gr NBT and 129gr SST Blems, all over moderate RL15 charges and .010" off lands) to get it on paper and see what was what. It took three shots to get on paper at 100yds. The next three NBT's went in half an inch. Shot two three-shot groups with the SST Blems and both were about 3/4".
The bore now looks quite different, being much lighter in color and with a much more typical amount of faint copper indicated. Not caked on like how it first appeared. I'm going to scrub it again and start load work-ups with better bullets and a chronograph. I don't know what the deal was with the condition in the pics above, but it looks like the rifle is going to shoot. If it doesn't, I'll be sure to mention it. Thanks for all those who offered insight to this unusual situation.
