IMO - it depends entirely on whether the shot is being taken "off-hand", or over a rest. I always reckon that when shooting off-hand, a scope only magnifies barrel shakes and makes the shot more difficult to control.

An illustration, the Big Game Rifle Club applies a penalty for scope useage at their competitions (shot at 25, 50 and 100 yards) because it was seen to give an unfair advantage. Those that had always used scopes grisled about this, but when forced to learn how to shoot with open sights, soon realised that they had been penalising themselves, and actually improved their scores with open sights!

That's with stationary targets. But with moving targets, I have always used shotgunning techniques to get the right lead. Naturally, the lead is different (why it is difficult to maintain high standards of shooting when you do a lot of rifle and shotgun shooting), but you do have to lead!

I believe that it is easier to do this with open sights. How do you factor in scope magnification on a running shot?

Can you imagine anyone fitting a scope to a shotgun??

And that's the great thing about shooting double rifles - it's the closest thing you can do with a rifle that feels like shotgunning!

The second best thing you can do standing up?

Besides, you can't shoot doubles off a rest anyway!

And if you accept it as a discipline, that is shooting open sights, preferably with a double since unless the animal is a) dead b)deaf c)has no mates, etc the second shot will be a moving shot, you will start stalking game to within range, rather than banging away over the car bonnet!

Comes down to why you hunt or what you call hunting, really.