400...... it is far more than a "gee wiz" excercise in engineering although it is quite an engineering marvel.
the rifle was brought to light after the inventor had a conventional dr double fire on him during a buff hunt. The rifle was his answer to avoid a re-occurance.
and 400 as you"seem" to be speaking from a position of knowledge..... would you please quantify your phrase "That a few take it seriously"

as for your question curl....... if you fire the right(or left) barrel only and then cycle the action, you eject both a spent shell and a live round and both chambers are then re loaded.
your aother queeries arent really worth spending a great deal of time on in answering as they are conditions that may arise with any firearm .....bolt or break action.

By the way ,,,,, it can be made to accomodate shotgun shells in your choice of guage ....28 or other.