That's a nice looking gun, Strawhat! Is that a Uberti ... or another make?
I have a Richards-Mason conv. of the Colt 1851 Navy into a .38. I acquired some Ten-X .38 Long Colt ammo loaded with Black Powder (from Cabela's) and it's a hoot to shoot! You can load .38 SP in it, but I've only used "Cowboy loads" since there's no point in putting anything through it that may stretch the frame or damage it since it's not a gun I'd use for self-defense.
Good shooting there, and keep your powder dry!