Re: NEED Your opinions
If you are concerned about barrel life shy away from the 6.5-284. If not, then that is what also came to my mind. If it is a concern, try the 308, or even the 7mm-08 and the 260 rem.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.