I recently bought a Springer Mil-Spec 1911, so I took it out and shot it a little to see how it would do. Shot 50 rounds and the only issue was one time the slide didn't lock back on last shot. Otherwise, it did fine. My question is while looking at the spent casings I noticed an indentation in the side of all the brass. I am far from an expert and it may be absolutely nothing. Thought I would ask those that know. Here are the pictures, give me your thoughts and suggestions.