I recently bought a stainless Ruger 10/22 and have probably put about 300 rounds through it. As I was cleaning it last night, I noticed that the finish on parts of the receiver (mostly on the inside) was starting to flake/peel off. I noticed little flakes of whatever it is that the receiver is coated in, floating around inside the action. My question is: is this normal break in/wear and tear or should I be concerned? Thanks.