Did you measure from the base of the case to the tip of the bullet?  If so did you adjust the seater die to make all the rounds the same exact OAL?

  How was the groupings?

wow, the 46 must've all gone right through the black square

Focus

Looks good. I'd say shoot the 46 grain(don't adjust your scope).  The group should fall in the same area as the 45-45.5.  If it does play with seating depth, of the 45.5, to bring the group together.

heads

I am still a little perplexed as to why one case in each charge weight had a primer flatten to that extent... 

This is the reason I started this topic, to see if this is common . . . apparently not.

Huuum.  Didn't change seat depths...  How about seating force?  Did some bullets feel more difficult to seat than others?  Did you apply any crimp afterwards? 

We'll get to the bottom of this.   

I have a chronograph if you'd like to get an idea of velocity

Looks good. I'd say shoot the 46 grain(don't adjust your scope).  The group should fall in the same area as the 45-45.5.  If it does play with seating depth, of the 45.5, to bring the group together.

Okay, shot the 46 grains...one flattened primer. I decided to load max, 46.5C, five shots one flattened primer. I shot some American Eagle 150 grain FMJBT...see for yourself. I loaded and shot 18 rounds with 45.5 grains, two flattened primers.

Okay, shot the 46 grains...one flattened primer. I decided to load max, 46.5C, five shots one flattened primer. I shot some American Eagle 150 grain FMJBT...see for yourself. I loaded and shot 18 rounds with 45.5 grains, two flattened primers.

Wow, that's some serious flattening but only on the ones that did. Crazy. So what is the history of the primers? Where did they come from? How do you store them? Could they be Feds instead of CCI?

Dogman,
Can you take a closeup of the side of the cases with flattened primers? I am looking for possible stretch marks or discoloration near the case head. If those marks exist it means a headspace problem on those cases. It might help to narrow down your issue.

Purchased the primers recently from SEC, stored properly. I don't have any Federal Primers. Wouldn't the AE rounds I shot use Fed primers? 

 Will do Inspector, probably this evening.