If that's the bullet I'm thinking of, I've shot some, in both repros and an original. (The accuracy was so mediocre in the repros I borrowed an original to try.)
The Navy just isn't a hard pistol to get on target, but the bullets didn't want to hit. None of the target strikes suggested the bullets were tipping, bullet diameter was a good match to the original but maybe a thou or so oversize in the repros--it might be worth trying to size some down to see how they do.
Loads were paper cartridges duplicating the charge in Hazard's paper cartridges (21 gr) and Johnson and Dow cartridges (17 gr). Group size for 6 shots of either load was in the neighborhood of 18" at 50 yards. (For comparison, the same charges and a round ball would group around 5-6".)