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^^^ I completely agree with Hyph ^^^

It is difficult to visualize what happens in the chamber at the instant of ignition because it all happens within milliseconds. But there is a sequence of events.
The firing pin strikes the primer and it ignites. The powder begins to ignite near the primer and burns forward and outward.
As this happens, the primer moves back to make contact with the bolt face. The case begins to expand and seal the chamber as the case is forced back towards the bolt face and re-seats the primer.
The faster the powder burns, the more instantaneous this process occurs thus allowing for less gas leakage.
Signs of over pressure can be seen by looking at the primer. As Hyph stated, the surface of the primer will be completely flat with a crater around the primer punch mark. The bolt face will also leave tell-tail rings on the primer (a mirror image of the machined surface on the bolt face). In cases of extreme pressure, the primer will fill the gap (ring) between the primer and the case head. This can be confirmed by punching the primer out and checking to see if the surface resembles the rim of a 22 lr. (where the face of the primer is larger than the diameter) because the primer is expanded prier to being re-seated in the case.
This is a slow-mo explanation of what happens in an instant.

As per the photos, the surface of the primer is still crowned and the outside edges are still rounded. Plus, there is still a ring/gap between the primer and the case head. I see no signs of over pressure.
I hope this helps.

Guys, If I missed anything, help me out.
 
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