There is no advantage to using smokeless in antiques. I think most people are scared of black powder because of all the BS about it being corrosive. It will eat your brass if you don't clean it, but it won't pit your barrel. The powder fouling from Unique is actually about as hygroscopic as black powder fouling, and will rust your barrel faster than black. It takes only five minutes to clean a black powder cartridge rifle properly. A little longer for a muzzle loader. So why bother using smokeless in the first place? To each their own, but I certainly wouldn't encourage the practice.