[danlbobb]

I was picking up my 45 acp brass at the range when I found several of these 9mm spent rounds.
They weren't shot by me.

There were many of them. They all had the same scorch marks and the same severely dented mouth.
Primers look normal.

If these came from my gun I would be concerned.

Any idea what might cause this?

 

[danlbobb]

Ya learn something new every day.

I had never run across that before.
And am unfamiliar with the operation of the weapons you all are referring to.