...it shot the primer out.......and the air pressure went pssssst!...
So, you telling us the primer was pssssst off when you opened the breech?
OTHER POSSIBLE COMMENTS:
That primer was probably pssssst off because you poked it with the firing pin.
What primer were you using. Some are more sensitive than others. CCI's are tougher than most and never get pssssst off.
Being used in a CVA would pssssst off any primer. (Uh-Oh, that's gonna draw fire.

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