I'm not overly refined in the double barreled shotgun arena, but I believe the selector is set to the second barrel through the action of the recoil.
If you get a chance, and don't have girly hands- dry fire the first barrel and then whack the butt of the stock firmly with the palm of your hand. (Probably will take a pretty good thump) Then try to dry fire the second. AFAIK the recoil sets the selector, I would assume internally- to the second barrel. I'm near certain the recoil doesn't actually move the external selector. If memory serves me correct the triggers are referred to as operating via the "Inertia System". By dry firing & moving the selector, you're just setting it to the second barrel without the recoil doing the work for you.
Let me know if that makes any sense, and even better let me know if it's true or not!
Sly
ETA: As to the "crack smoking" part of your question, your from CA- that was a reduntant question so I won't waste the time typing a response.