If you have everything but the bullets, you are also set-up for .243Win. There are a lot of advantages to the .243Win worth considering. If you look at the performance, you will see that the .243, at least to 600 yards, is performing as good if not better than the 6.5CM and way ahead of the .308. True, the bigger bullets have more energy at range and if you are looking past 1000 yards, the 6.5CM is likely a better choice.

26" fast twist barrel is some of the benefit of course. But lower cost and recoil is a plus with the .243. If you look at cost per round fired and factoring in 3 barrels for the .243, the total cost is actually a tad less for the .243, and barrel prices will likely drop as the competition and aftermarket catches up.