Along the lines of the photo, the barrel does not seem bulged on the axis shown, would have to be "looking down the barrel" for the other axis.
With that type of result, didn't the rounds fired "sound" different? No hole in target, etc,..?

That's similar to how Brandon Lee was killed, .44 Magnum bullets with no powder, but still had primers, gun fired. Primer manages to get the .44 Magnum bullet "squibbed" in the barrel.
End Scene,....
Next day, poor prop. mgt. and inspectors reload .44 Magnum with full power "blanks". Squib STILL in barrel.
Blank Fired, enough to hit Brandon Lee in abdomen at point blank range,..... actor killed.
This shooter is really lucky, AFTER SEVERAL SQUIBS, to not have the whole thing kaboom in his hand, face.
Although that is some quality cuts in the barrel for examination,..