designed to use goblin shotgun shellsprint parts (2 pins) get 6x32 screws + springs for pins + pins to old barrel to handles instert pins and springs then make a bur to hold spring on assemble with screws and a small screw about 1/4in from the back of the barrel inbetween the barrels cut small peice of metal to reacch from screw hole in the middle of the handle to the srew