[jepp2]

Have you checked the inside of the cases with a bent paperclip? This will give you indication of incipient head separation. While the bright spot seems too forward, never hurts to check.

When you size your cases how much are you setting the shoulder back? Another way to ask is how are you adjusting your sizing die?

Seems to be less related to crimp and more related to other issues.

Flat primers can be more of an indication of excessive headspace as much or more than an indication of over pressure.