It's highly unlikely, but a picture of the ammo would be helpful. Some people get a big dent in their truck and call it a "ding". Lets see what your referring to.
I believe Federal uses reloaded military cases and sells them to civilians. Sometimes cases will get a small ding from the ejector. This won't hurt any, though it will reduce the number of reloads the case can safely take. These tiny dings will fire-form out when you shoot them.
I should note that 5.56 AKs ding the brass to the point where it's actually FOLDED. These cases are NOT reusable. An AR15 or M16, on the other hand, create a relatively minor mark.