Thought I would post this here as I think I have the best chance of getting a true answer. While shooting yesterday I noticed that the bullet holes had a black ring on the paper almost like carbon or oil was on the bullet when it went through the paper. I do not recall this happening in the past (no I don't shoot holes in paper much). Can anyone explain? Tikka T3 in .270WSM and .270Win. Both rifles cleaned meticulously to remove copper fouling a few weeks ago. Shooting a mix of ammo so not manufacturer specific.