'Parashooter': As always - Great explanations and graphics! Thanks.

P.S. - IIRC - A primer projecting to the rear that has maintained its rounded corners ('cup-shape' and not flattened), can be a sign of low pressure in rounds. On Firing, the primer was pushed back to take up 'free play', but, there was not enough pressure to stretch the cartridge case and force the case-head rearward against the bolt face (which would have re-seated the fired primer).

IMHO - If there is no evidence of gas leaking from or stretching primer pockets and cartridge cases are not separating, the brass is doing its job. Use the cases as fire-formed. Just trim brass as needed and Neck-Size.