Nitro

I think that the trajectory of the 9.3 is about optimum for a Double. Even at 3"/100 yards that is only 200-250 yard accuracy. The flatter shooters wouldn't be anymore accurate, even with a scope.

All the ones you mentioned would be more than adequate at those ranges and would be fun to use. I have a 303 but it is open sights and past 100 yards I need a scope now so it sits more than it deserves.