Just received two Brownell AR mags yesterday & used them today. While wiping them down with a little Rem Oil after use today, I noticed the finish wiping off on the clean paper towel. Also noticed this w/2 Colt mags that I have never used today, doing the same thing. I did not use the Colt mags today, they are still new. Also w/the Colts, they are 30rd mags, was unable to put more than 26 in & noted inside the mag a coating of some kind. For a lack of a better word, mold/corrosion? Plus the green follower would get stuck several times when unloading that mags. No problems w/other AR mags I have. Anyone else experience this? Can a AR mag be disassembled easily? Both the Colt & Brownell have identical bottom construction.