9mm Kimber Micro9. I'm getting this odd brass spot in the firing pin indent. I get these in CCI SP but not in what I assume to be Winchester in some reloads from a small commercial reloader; or if I do its hard to see in the brass-colored primers. My theory so far is the firing pin strikes, bounces back, or is pushed back and the primer metal flows into the channel, then the nickel plating is sheared off as the case is ejected. Anybody seen this?