So many of us out here started our CF rifle shooting careers with 243s, that it's hard to think of life without a 6mm rifle of some sort. I bought a new M70 sporter in 243 in 1968 for $123, put a used Weaver K4 on it, adjusted the trigger down to 2lbs, and thought I had the world by the tail on a downhill pull. Used it for prairie dogs, coyotes, and on paper. However, through over 30yrs of competitive shooting, I didn't get another 6mm until I had a 6 Dasher bbl done for my Nesika K Palma rifle in 2004. That kinda opened the floodgates though, as I've built myself numerous Dashers, 6x47L, 6XC, & 6RATs, since then, and will be building another Dasher on a Bighorn TL3-SA & 6XC on a trued M700 this spring.
Bbl life may not be as good with the 6x47L/6XC/6CM as it would with a 6.5 case of the same capacity, but the bullet selection is excellent & getting better, plus they're less expensive than 6.5mm bullets. Try a 6mm - you'll like it.