A couple of weeks ago I tried out Black Mag 3 for the first time with mixed results. After the range session I went home and cleaned the gun and stored it as usual. Tuesday I went back to the range and when I ran a patch down the bore to clean the oil out, the patch came out with some brown, rust looking stuff on it. I thought back through my previous range session and cleaning of the gun and the only thing that was different was the fact that I had shot some BM3 the last time out. My cleaning procedure was the same as always but I have never seen this brown stuff come out of that barrel. It cleaned out with just a patch or two of solvent and a couple of dry patches and the gun shot as good as ever. Anyone else seen this or have any thoughts about it?