308 is my favorite round, and it wins the factory ammo contest, hands-down.
Having said that, I also like (and have) the 6.5 CM. Inside 600 yards the 6.5's "superiority" means jackchit. And, with 6.5/140's the difference in recoil vs the 308/165 isn't that great. And with a 308/150-155, there's essentially no difference.
My advice would be to keep the 6.5 and add a 308 too. But barring that, the 308 in conjunction with the 243 you already have is a nice combo... but for me, I'd ditch the 243 and keep the 6.5CM WITH a 308 Win.
