I picked up an 1858 5 1/2" barreled Remington from Cabela's on sale last year. Tried to fire it with #11 caps but it was a disaster. Caps wouldn't stay on and jammed up the action. Picked up some #10s at Friendship but hadn't had time to fool with it. Yesterday I got the time and what a difference having the right caps made. At 15 paces the group was a ragged hole but 4" low. I was only loading 20gr of 3F because that was the only spout I had and didn't have much time to try a full load because rain was coming in. I think with a full load of powder it might print pretty close to POI.
I'm pretty impressed with this thing at this point, especially for the price. With my eyes I'm thinking about opening up the rear notch a little to give a little more daylight on either side of the front sight.
Bob