Yeah no. Unless I was hunting a Tyrannosaurus, it has no use being in my arsenal. Then again While I am a pretty big guy, that thing would probably wreck my shoulder after the second shot. Props to that guy for sure.
Benching 400lbs is no small feat either.
Most I was ever able to was 325.
Anyway, neat toy. Not sure what practical use I would have other than maybe part of a booby trap or some kind of automated turret that could be fed like a cannon. Because that is more or less what you are looking at with this thing. A small cannon.