What do you use to eliminate the copper in the barrel? What do you change when it becomes very difficult to eliminate the copper? I am having problems with a Browning A-Bolt in 30-06, even though it has been cleaned about every 50 rds or less, I have not been able to get the copper from the rifling. I have not seen this before in the gun?

Boretech Eliminator is what I use. It will get the copper out. Note that if you use brass jags on your cleaning rod, patches will still show up blue even after the copper is long gone.

Also note that some barrels like having a little copper for best accuracy.

603, I am still seeing copper on the riflings not on the patches.

Is it still shooting well?

JB bore paste will knock it out quickest. I put it on a patch wrapped around a brass brush and in less than 10 passes it's clean unless it's really bad.
Then just run a few patches with Kroil or whatever cleaner you like to remove the JB and it should be squeaky clean.
I rarely have to do the process but when you get the one of those barrels it's been the fastest way to get back to clean.

I think Fireman asked the important question - How's it shooting?

Time was, I wanted all the copper out, but I finally learned that some barrels shoot better with a little copper. Nowadays I clean the carbon fouling out and check accuracy. Depending on how it shoots then, I'll either leave it alone or, if accuracy is not back to where it should be, then take the copper out.

As for what removes copper best, I've used JB Paste and still have some, but that Boretech Eliminator removes copper better than anything I've used before. And, I'm not wild about using an abrasive paste in the bore.

JG, as good as can be expected with a 70 YO pulling the trigger. I am not unhappy with the accuracy. I will know tuesday if the cleaning I gave it helped accuracy.

Point being, if it's no fouling, little fouling, or heavy fouling, the most important thing is how does it shoot? If it's somewhat, or very fouled, but still shooting well, then don't worry about getting the barrel spotless inside.

https://www.youtube.com/watch?v=RVKp0h9no3o

I have a similar home-made set up and if you really want the barrel as clean as the day it was made (cleaner?) just use this method.

You will most likely find that the barrel needs some carbon and/or copper in it for best accuracy.

A little copper left in the barrel can be less damaging than being to aggressive to remove it.

Bottom line is how it shoots. Good advice.