I make a point of standing my freshly cleaned rifle on its muzzle in the gun vault. I put a folded cloth under the muzzle and always get a very small blue circle under the muzzle after a few days. Perhaps I am not getting my bore as clean as some might prefer, but this is after a reasonably uniform and comprehensive cleaning routine. I assume that this spot is solvent that might have run back into the action, maybe into the stock/bedding eventually? Seems like it always has a blue tinge so I am not getting all of the copper out, even when I repeat the cleaning procedure a couple of times. If I am going to shoot the rifle in a short time I always run a final patch lightly soaked in Shooter's Choice down the bore before storing it. If not I dry the bore after the solvents, then run a patch with RIG or Shooter's Choice Rust Prevent down the bore. Interested to hear if any of you guys also store their rifles muzzle-down. Be interesting to hear if you get similar residue stains. Also any pros and cons on storing rifles muzzledown, rather than horizontally or muzzleup.