The "Catamount Fury I and Fury II" shotguns.
http://www.americanrifleman.org/blogs/cia-catamount-fury/
I wonder who makes them.
They have LRBHO and internal chokes
Owner's manual I found online:
http://www.scribd.com/doc/113430510/Century-Catamount-Fury-Semiautomatic-Shotgun
Also a cool recoil reducing AK butt stock
http://centuryarms.biz/proddetail.asp?prod=ST1013