No denting is not normal, and is indicitave that something is out of spec or the heat treatment is bad...
In high round count AUGs, the teeth will sometimes break off. However, this is a wear issue, and occurs after several thousand rounds. It is not the same as the denting or peening seen on low round count guns that has been reported with some MSARs. Denting/peening is not normal to AUGs...
Okay, thanks for the replies. Already sent mine in for a different issue but mine was starting to do that before I sent it in. I was getting this issue confused with the bolt sleeve breaking. Thank you for the clarification.