There's no bigger fan, owner, user, promoter of T/C products than I've been for 18 years.
But having said that, like many companies they've had their quirks over the years...the step down jag being one of them.
Somebody had the brainstorm that a stepped jag could clean or lube the upper powder chamber of the patent breech...but it was still to big to get down into the smaller diameter of the lower powder chamber, and was ultimately discontinued.
Always been surprised T/C hasn't evolved the jags they do sell to have steel inserts like the excellent quality Treso jags.