Glad the JB's worked well for you. I had a similar experience and I think it took me about 200 passes with JB's before I was satisfied. I bought a Pro Hunter on clearance that had been used as a display model it's whole life, about 4 years judging from it manufacture date. It literally had dust bunnies filling the bore. Once I got all those out I was horrified at the rust in the bore. Long story short, a couple hours with JB's and when I was done the bore was better than new.
Now to the range. Make sure you post pictures and a range report.