I wonder ....

How regulation is maintained when swapping barrels?

eg one could have the following:
1. Double rifle 9.3x62 set;
2. .222 upper and 8x57 lower repeater; and
3. 12 gauge upper and 7x64 lower repeater.
4. Any combination of the above?

Given the sights sit on the upper barrel, and a scope in QD mounts would also be mounted on the upper barrel, presumably a different scope might be needed for any and all combinations, but how would two rifle barrels maintain regulation?

The shotgun being only in the upper barrel limits performance. My feeling is a pump action repeating shotgun with a single shot rifle barrel would be more useful than a repeating rifle with a single shot shotgun.

What the balance of the firearm is like?

The weight of the firearm is reasonable compared to other repeater double rifle/combinations previously seen. IMO.

What do you guys think?