I have found that some barrels hold on to copper way more than others!I have a Weatherby Vanguard 300 weatherby mag that loves copper and hates to lose it but I also found out,due to a borescope that as others have said that carbon protects copper so you have to get the carbon out first.Get that out and then go for the copper.Don't be surprised to find layers of copper then carbon several layers deep so keep rotating.
I use KG products but ran out and got Boretech copper remover and C4 Carbon remover and use that but have found out Free All cleans carbon WAY better than any product I have ever found and it's cheap.We used Free All to loosen nuts and bolts on autos for years and now I use it to to clean carbon.
Now my rant is over
I use KG products but ran out and got Boretech copper remover and C4 Carbon remover and use that but have found out Free All cleans carbon WAY better than any product I have ever found and it's cheap.We used Free All to loosen nuts and bolts on autos for years and now I use it to to clean carbon.
Now my rant is over