why not run the 6.5x284 if your looking at the 140s . a couple hundred fps is nice on the big end .
Barrel life almost 3 times less with 6.5x284 and ammo price higher.
3X longer may be a bit of a stretch. The 6.5-284 has often been over stated as a barrel burner. Are they harder on barrels than some others, sure. Does that mean they'll torch a barrel in 800rnds, that's largely dependent on how you shoot it. Get em hot and keep banging away on the trigger and it'll be like a blow torch in your chamber and there won't be much left of it but use a little common sense and let it cool between shots and it'll last considerably longer. I'll bet the majority of the bad rep the 6.5-284 gets as a barrel burner came from the benchrest shooters but you have to remember, they'll often wait for the wind to be at it's best then shoot as fast as they can to get all their shoots in while the wind is at it's most favorable.