Well . . . those guns came out of Japan. The steel shot recommendation on Parker Reproductions, also made in Japan, was that you shouldn't shoot steel through a full choke barrel. I think Stan's choice is a reasonable one: Mod (or more open) should be fine. Those guns are neither real old nor real delicate. And I don't think we've heard any horror stories about ring bulges (or worse) as a result of shooting steel through modern Japanese doubles--although staying away from the steel shot/full choke combo seems a reasonable caution.
