Spring cleaning several of the scoped uppers (they get a little more attention in the bore than the full ones for the M16A1 - which are clean but maybe missing some of the rifling with age and a dozen cases of ammo ;-) and again can not get over how much "black residue" (assume carbon but have not checked yet) comes out of a barrel that was "clean" using Hoppies or Shooters Choice (use new brush and patches with either until clean for three days in a row and then leave the Hopplies #9 wet in the barrel over night each day to remove a little more copper).
Using a clean brush, rod, bore guide and brushing with Kroil three sets of ten passes, the cleaning patch comes out black. Repeat a couple times and then back to Hoppies or Shooters Choice to get the next layer of copper. Using MPro 7 I get a similar but not quite as good result.