Whoa. Pretty cool concept, but I fail to see a true advantage over a O/U. Still, from an engineering stand point, it's :fuckyeah:.
http://www.impactguns.com/data/default/images/catalog/535/ber_ugb25.jpg
http://resmoback.strefa.pl/images/beretta330.jpg
http://t0.gstatic.com/images?q=tbn:ANd9GcQ2XvNQpQAlcz5URPuKuwbjk_KKVwzrv4Z96lVJqP5CPKsT0TuGnoDBwLR2
Video of it in action:
http://www.youtube.com/watch?v=NTGm5y7LADk