Newbie here- Posted yesterday about getting rid of carbon build up. This is what I have observed/learned in the last day. I have a 6mm with a tough carbon ring...with the advice of fellow members I'm working on removing it...not an easy thing to do. I was able to remove all the carbon fouling in the barrel with JB Bore Paste, looks great except for the ring. Worked on a 30-06 yesterday and today that was neglected. Heavy carbon/copper fouling. Soaked over night with patch out and and then used Boretech Eliminator and carbon remover following their instructions. According to the patches it is clean. According to my new teslong bore scope there is still heavy carbon fouling. I did a JB treatment and removed a good bit of carbon. Slight carbon ring and still carbon streaks in barrel. Used the Boretech carbon remover again, soaked for 2 hours and patches are clean. Bore scope still shows a lot of carbon. Will work on it some more. My observation is this and I would like for the more experienced shooters to confirm or correct me. On both rifles I cleaned with different solvents for copper and carbon until the patches were clean. This involved doing many sequences with the solvents...including using brushes. My feeling is you have copper/carbon "fouling" resulting from a normal amount of shooting in a clean barrel. This fouling is removed without to much trouble with good solvents, brushing, patching,etc. Then you have my issue which is "baked in carbon" from having never properly cleaned a barrel that has been shot a lot. This baked on crap is not removed by the solvents. JB, Iosso, etc is needed. The eye opener on all this was my new borescope. Even after multiple sessions with normal solvents and the patches showing no sign of fouling, the scope showed a lot of carbon still in the barrel. I've read where many of you say the bore scope is the only way to know and I'm a believer. The teslong is the best $50 I've spent in a long time.