Re: building another lr rig
For a 308, I would never go with anything slower than a 12x. With a 12x you can stabilize 200's (except for all copper) but it is not an optimum combo. For 165-190's, the 12x will serve you well. For 190-210, the 11x will do well. Anything over that go 10x.
All that said, the 11x works well with 150-190 grain bullets. It is my favorate twist for the 308 but my next one will be 10 for some of the mono metal bullets.
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.