Flattened primers with no other pressure signs?

[Ckleeves]

There's a good chance your work up will be the same after you fireform your brass.
Depending on how much shoulder set back you do. I don't get serious with brass until the third firing with neck size only. I usually see flat primers on the new brass. After I get the brass "stabile" I get serious with load development.

Ya that's what I have always had to do in the past. I never put much stock into virgin brass. The accuracy was much better then I have had in virgin Win brass however.