This was reloaded by myself. New Winchester Brass, CCI magnum primer, H380 38.0 grains, and Nosler V 55gr.
I see a small "ding" in the primer cup. Decap and inspect the primer. It may have been defectve or split.
Didn't I read somewhere that this is a typical sign of a head-space issue?
That looks like a bad primer. I've seen in the past primer with defects. Look up defective primers and you get a lot of pics like the one above.
I was curious, so I did just that. Got this picture:
That's exactly what I was talking about. How is your bolt face? Can you post up a picture of the bolt face.
Was your round a reload or factory. I would be calling asking the to replace my bolt if this happened to me.
RSW
Which was from this thread: Pierced Primers - The Firing Line Forums
Did the round fire? I've seen an occasional new brass with no flash hole.
What was your COAL exactly?
BTW, whatever happened with your 300 WinMag troubles?