At what point do you consider a gun barrel to be clean? The reason I ask is because I can clean my Rem .270 with patches and solvent until the patches come out perfectly clean. Then run the bronze brush through it and the next patch comes out nearly black. I've been doing this all day now and the patch comes out black everytime after you run the brush through it.

I use Hoppe's #9 solvent, cotton cleaning pathes, and a phosphor bronze bore brush. I clean the gun after 4 to 5 rounds when sighting it in and anytime it is shot during the hunting season. Am I doing/using something wrong or is this normal?