A friend lent me his carbine barrel in 6x45. Super nice round to shoot in a little Contender Carbine! If I were buying a barrel I would get what you did, the TCU version. Can't imagine a nicer round, unless you are a .25 fan like me and have 'overlooked' a very good rimmed round for the T/C, the .25-35 Win! Even neater maybe, the Ackley Improved .25-35 Win.
Just thinkin' out loud.