Kees,
I think the T/C only had about a .005 deep rifling in the first place, so it almost started out as a smooth bore.
I had never heard that T/C made a .50 cal smoothie. Of course, I never much paid any attention to anything .50 caliber, so that could be a big surprise to me.
RE: the ante chamber, I shot T/C's for a lot of years and never paid the least bit of attention to that. And after popping a couple of caps, I never had any ignition problems either. If you want to clean it out, a .30 caliber bore brush should fit into it for a good scrub. Then you can put a cleaning patch over a .22 cal brush to dry it out.
Have fun with the new smokepole, Kees. Still haven't shot mine. Seems like every darn rendezvous and rifle range on the west coast is cancelled or closed for the duration. Takes some of the fun out of life.
After not pouring a single round ball for years, I sold off most all of my casting stuff. Then I got our rifle and decided it would be a good idea to pour some round ball for the smooth bore barrel. Now I gotta get a new ladle and a mold and stuff. Right on time, eh?
John