I have discovered that there is a difference in the amount of copper left in my bores depending on the choice of bullet that I shoot. I clean the rifles after every range session and I am seeing a definite increase of fouling from the Nosler Accubond than from the Berger VLD. Both bullets give excellent accuracy (to my ability). I am using the Bergers in my .300WM and the Accubonds in .308 and .30-06. Does the type of powder have any bearing on amount of copper? I am using H-1000 in the .300 and IMR-4895 in the other two. Or--is it that some bullets just foul worse than others? I have about decided that when I use these Noslers up that I won't buy more. The .308 and the .30-06 did not seem to get fouled as heavily when I was originally shooting the Sierra Matchkings. I know from other threads that some barrels simply foul worse than others. Both the .300 and .308 are the newer Milspec 5R rifling and the .30-06 is an old M700 with carbon steel.