I totally agree with the others........................Sweets or Cr-10 is the way to go to kill the copper. Follow the instructions carefully on either of them and it WILL take care of the copper - Especially in a new barrel.

And again - do NOT use any bronze or brass utensils with these cleaners............plastic jags, nylon brushes, or bore mops work very well with them. But these solvents will attack bronze or brass and give you false readings on your patches.

As a general rule.....................clean the powder fouling out like you normally would with your standard solvent, then follow the instructions on the copper solvent for 2 cycles - patch dry and then repeat with your standard cleaner & copper solvent again. I do this because the copper & powder fouling can layer in the bore and this method is effective for that.