Help reading a primer, overpressure?

[Richard P]

I'm going sizing a batch of range brass while the hurricane passes through. I've found a few weird primer strikes like this. Is that a sign of excessive pressure, or just a weird firing pin?

Follow-up question. If it IS overpressure, would you load it up and shoot it if web shows no visual sign of damage and it plunks into case gauge after sizing?

It appears the primer has flowed into an oversized firing pin hole. High pressure usually flattens the primer to the edge of the pocket.

 

[gyppo]

That is not an round that was loaded toward the high end of 9 mm range. The round was still under pressure when the weapon was out of battery. The firing pin indention was blown back out after the breech face moved rearward. Best guess is a mac or sten where someone was using a light recoil spring to slow down rate of fire but that is guess. Could have been a highpoint with weak or wrong spring or maybe even a missing spring also.