I went to the range today with a friend who is a parole officer for the county. They are required to carry and qualify quarterly, so he showed me some of their drills etc. One thing he showed me was holding the slide on a semi-auto with the palm of your hand. It forces all of the gases out of the front of the gun leaving a massive blast wound. This does force you to rack the slide to clear the shell though.
The picture is from his .40, the other is me shooting my two 9mms.
