NE 450no2--

I would luv to see what your 9.3 does on paper at various distances.
You could shoot the scope and note the point of aim as well as the calculated POI of each barrel.As you said,it could work well with 4 shots per barrel per distance by averaging the 2 pairs of farthest shoots from each other and taking the median distance of each pair from each other.

Wish I could do such an experiment but my 500 is no long range shooter.

I would bet that some ignorant gun writers would swallow their cud and choke if they saw what a regulated Double could do at distance!! Secretly I think many labor over the delusion that Doubles are kinda like bow and arrows,a primitive outdated club for close range work. Boy would they be surprised!!