I believe that is correct - where else could you get the nice big leverage provided by the barrels. I suppose it could be a function of the top lever but that would probably require a larger top lever and some weird internals to translate the sideways motion to a rotating rearward motion. Or you could add a separate side lever to do it ala some of the drillings which use a separate lever to cock the rifle barrel. There is the Kreighoff double rifle which has the enlarged thumb safety that cocks and uncocks the hammers.
