The first 100 or so rounds literally disintegrated into the glass. The glass absorbed 100% of the bullets kinetic energy and you could see lead and copper "dust" at the site of impact on most of the rounds. As time progressed and we started pumping more and more rounds into it the bullets started to stay intact but would be lodged into it and finally the last few were falling out on the back side.
Let me say, I would have NO qualms about bputting my life on the line behind one of those. I think the glass itself took close to 500-600 direct hits and still held it's overall shape.
Neato! You should have taken a close-up pic of the front!