The Browning B-92 that I had 20 years ago had the real slow twist barrel, I think 1 in 38. I couldn't get that one to group 240s well, although I know it should have. I sold it and got the Miroku 1892 Short Rifle in 44M. If memory serves me correctly, the Miroku has a 1 in 24. Someone jump in and correct me if I'm wrong.
Since I have the Williams (temporarily) mounted on the side of my Miroku, I have a WHOLE lot more adjustment, sight wise than I ever did with either the factory buck horn or the Skinner, barrel mounted sight.
This Miroku 44 shoots different loads to very different points of impact at 100 yards. Now, with a truly adjustable rear sight, I'm no longer stuck with shooting just one load. So the last few days, I've been playing with 180s, 200s, 225 Flex Tips. I have found out that my old 429421/ 20g 2400 loads (single shot) shoot pretty well. Elmer would be proud.
I find that shooting iron sights well, which is hard to do, very satisfying. The apature helps tremendously. My front bead is .075 inches in dia, which means it's 7.5 inches at 100. You'll have to excuse me. I'm going to go look for an aperture front sight.