I just purchased a Rhino turkey choke for heavy shot (.673) and put it on my Franchi 912 Variomax 12 ga. Even at 50 yards it patterned unbelievably. It is ported, made of stainless with an acid wash to make the exterior golden brown, and is a true quality choke. No comparison with other chokes I've tried. You can shoot lead in it but it will not pattern as tight as the heavy shot. It should perform close to the same in your gun.
I just purchased a Franchi 912 Variomax 12 ga. 3.5". I want to try it for turkey hunting this season but I can't find any choke tubes that specify for a "Franchi". Is it safe to assume that a tube for a Benelli will also work in my Franchi?