copper solvents

[Catfish]

I`ve used Sweets 7.62 for years and it works. I have worked on some barrels that were fouled so bad that it took a very long time to get them clean and one that I never did get all of the copper out of, but it did shoot around 1/2 moa when I got done, even with the copper I left in the barrel.
I cannot figure why you did not get blue on your towel. It should have desolved copper to the point of saturation of the volume of soulvent you applied, or at least that what I would expect. I may put alittle Sweets on a bullet and see what happens.