Gentlemen,
Here is my answer to the RBL. This is a converted 16gauge FN sidelock, now 20 gauge, rifled 1 in 20, with 20 inch barrels, it weighs in at 6 1/2 pounds with red dot scope attached. It will shoot 1 inch right/left groups at 25 yards or about as far as you want to shoot if you can hold it right. The upwards recoil is brisk but manageable. The scope is a fourth generation Aimpoint. The rib was drilled and taped in three locations so that a conventional scope can be used in the regular position or either of the sights can be mounted in the forward "scout rifle" position.

I had been asked about shooting buckshot loads in this gun but I knew it would slig them out in a donut pattern. I did decided to try a double round ball load to see what it would do with that kind of load. Two .535 balls were loaded inside a Winchester AA wad with a 15% reduction in powder because of the added weight. We found that one ball would usually go to the point of aim but that the other would vere off to the side. The amount of spread was related to the distances shot at. I think if I had had slightly bigger round balls to load in it, it might have done even better. They were not a really tight fit inside the wads but still worked well enough to use as finish up shots on wounded game.

The left hand shooter is my brother Doug. In one of the pictures, he is pointing to a hole that was made at 25 yards by one of the round ball loads and at the aiming point. Usually the spread was about 6 to 12 inches for the two ball loads.