RRB259 :WhatI would suggest is buy two new reloading manuals ie; Nosler etc, try andpick what bullet you would use. I use 165 gr Noslers with 4350 assuming you choose 165 gr look at manuals for that bullet and see which powders give you the most velocity withleast pressures, there are so many new powders now and work around the best of those powders. Its slow but go up in 1/2 grs and watch for pressure signs "primer flatening out etc. If you want to shoot at long distance as you mentioned you got to have the bullet moving fast.
Just neck size your brass,and I believe in neck turning your brass
Good Luck