T/C also makes a ML only Encore...im not going to look it up right now but you can find it in the ML section at Cabelas. That one will not work with other barrels. Make sure your not looking at that one if you want to replace barrels in the future.
The TC Pro Hunter FX is the muzzleloader only and will NOT accept other barrels yet looks exactly like the Encore Pro Hunter.
Encore® Pro Hunter FX - Thompson/Center
I've been researching the crap out of TC muzzleloaders recently.