It is totally, completely, awesome. I didn’t think there would be anything like that here in Australia, but there is! Henry’s are cool, there are some other guns I would have liked to have, too, but was happy with my Winchester 73 (I think I called it a 72 up there, small brain). .357 has become very popular in Cowboy Action, but like you say, it depends on the event. .44 Mag, nice!
It’s very exciting to see the Championships, and Man (or Woman) on Man, two people competing next to each other, winner is last knockdown. Very exciting and visual, and it’s always up/down/up/down, you never really know who will win, even with a two handed fast shooter against a one handed black powder shooter.
It was a lot of work, especially here in Australia, but absolutely worth it. Great folks and you get to dress up in costume. Go to an event (everyone will probably give you a shot).