It has become conventional wisdom, in the last few years, to not use McCormick mags, or mags with McCormick followers, in alloy-framed guns. I don't know why it wasn't a problem for the twenty years prior, but recently it's become a problem in that the follower can tip forward and peck away at the relatively soft material of the frame. Colt 8-round mags that I've seen have the McCormick follower, so you might want to swap those out.
"A grip safety is just another excess moving part. I have never known one to prevent an accident, and moreover, it is difficult to postulate a circumstance in which it might." Jeff Cooper