They had a case like this in Canada a while back. Guy had a protective vest plus a couple of phone books. (No idea how thick.) Buddy shot him in the chest with a 12 gauge. In this case the vest did its job, but the point the idiots missed was that a modern vest is designed to stop penetration, not the whack. The guy ended up with a couple of broken ribs and some spectacular bruises. Last I heard the local law was trying to figure out what to charge who with.