I have had this Colt 2nd Gen Dragoon for a while. I stopped shooting it because the hammer started sticking at half cock. I sent it to Gary Barnes to fix it and recently started shooting it again. Before it always shot a foot to foot and a half high and three inches or so to one side(can't remember if it was left or right). After I got it back it still shot the same but I had always shot it with 30, 35, 40, 45 or 50 grains. 2F and 3F in 5 grain increments. Just for kicks I tried 32 grains 3F and it still shot high of course but suddenly it started shooting to center. I then tried 37 grains of 2F and again it shot high and center. The 2F produces a tighter group than the 3F. So I do believe I have the right load for this gun now, 37 grains of 2F. All loads are with an appropriate amount of Cream of Wheat filler to bring the ball close to the chamber mouth, .457 round ball and homemade lamb tallow/beeswax lube over the ball.
So far this is the only gun I have where changing the grains changed the windage, not just the elevation.