Hit or miss is never a good plan for finding an accurate load. Not knowing your experience level........

Use the OCW method on three different targets per projectile with at least 5 loads. .3 grains apart for the 308 Ie...41.4, 41.7, 42.0, 42.3 etc.... for the 178. There are higher accuracy nodes but you should find a sweet spot for the 178 in that range. 4064 is my choice of powders from 300 to 100 in the 308 with the 175 class projectile. All day every day.

Primer: WLR works fine with 4064. The unobtainium FGMM is the other primer to use.

Scale: You will need a very accurate repeatable scale or powder drop to achieve this. Beam scales are fine if you know how to care for and tune if necessary.
Opinion: Electronic scales in my experience drift too much unless you get into a higher end scale. Gem Pro is hit or miss from my personal experience and is not worth the risk for most people. So unless you have a Prometheus you may be better off going beam. Check often.

Brass: New is preferable, quality is optimal. Weight sort them as best you can if you like that option. Do not mix brands.