Ok, here is a little background on this particular rifle. It is a Remington Sendero in 7mm Rem. Mag. It was bought new. First thing done was cut a case apart and make a chamber guide. Then using 4A compound the barrel was lapped from chamber to muzzle. Used a nylon brush with a wrapped patch and the compound worked into the patch. Not that this is acceptable, it did polished the rough barrel up nice. Loads were worked up using nothing but moly coated bullets. The load got excellent velocity, and has shot several groups under 1/2" at 300yds. This load has shot well to excellent every since. The rifle has been cleaned regularily over the years and has always shot exceptionally. I got the STW and decided to change up the load a bit on the standard 7 mag to use up some on hand lighter bullets. So I got to cleaning this thing yesterday. Did a very thorough cleaning and got clean patches, however could still feel a bit of rough going through with a clean dry patch. Got out the Sweets, and got some more crud out. Then clen patches. Still felt something so figired I would run some JB through just for kicks. Ran two patches through and both came out completley black. Ran some more Butches through and got blue. REpeated with the JB and more black. I am sure that this is layers of moly and everything else on top of one another. I guess what I am wondering is when using the JB on a patch does it ever come out clean when the crud is all removed? Right now I am hopeful that between the JB and Sweet's mixed with Kroil, that I am about through, but still am getting the black patches out.