Just about 95% of my cleaning "gear" is BoreT but I like Patchout for Copper, I have one factory barrel that coppers up nicely and PO generally makes quick work of that. I have also seen where C4 leaves a barrel "clean" PO still lifts up a little bit of carbon without to much elbow grease, the BT rods run very nice but one of mine started "flaking" the finish so that rod will get replaced by a Dewey.