GunGeek, is yours one of the early PTR models? I read about some fluting differences in the early models. Mine (GI model, new production from 2-3 years ago) left the brass looking almost exactly like your second pic. No concerns about reliability with that one.
I've never owned one. A very close friend of mine bought one about 6-7 years ago and I have shot it on several occasions. His has no discernible dents on the brass. I have another friend who owns both a PTR semi auto, and a full auto H&K G3, both of which I have shot on several occasions. The H&K G3's brass actually looks considerably worse than the brass in the lower picture. Both of the PTR's that are owned by my friends have extremely shallow fluting. I'm not sure if that's still the case or not.
