Originally Posted By: pahntr760JMO, but a 6x45 is an easier route. Not to say the TCU doesn't have its merits, but fire forming for minimal velocity gains.
But if you want it, go for it. I am considering a bolt action, 9 twist, 6x45 launching 95 gr TMK's.
I just got a GM barrel chambered in 6mmx223 aka 6x45 with a 22" medium sporter 9twist. Its a great cartridge especially since you can get brass dirt cheap. Great little round.