Re: .308 Win. Load Recommendation
For your 24" tube, try starting with 42.0 of RL-15 and Varget for the 168 and 46 of Varget and RL-15 for the 155. These are just to start, work up in .5 grain increments from there. Try those 2 powders, and choose the overall best one. One of those will give you what you want.
Long range shooting is a process that ends with a result. Once you start to focus on the result (where the shot goes, how big the group is, 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.