Nope. Since 1986 you can not make any new FA firearms unless you are a manufacturer with a note requesting a sample weapon to be made. If your friend wants to make the sten a semi auto SBR then he can make it , but it must be a semi auto and the SBR because of the stock. He can make it semi auto with a pistol grip and not have to register it ( or pay the $200 stamp tax ). Just a thought.