Guns are "funny" things. What shoots, or is reliable, in one may not be in another.
We tried several powders a few years back for hunting ammo for my son's M1A. We used IMR4895, H335 (he likes that powder for his .223 loads in his AR15), W748, Varget, and a few others. IMR4895 gave us the best groups (it does not meter well in a powder measure, so more effort is required).
Your .308 may do fine with the same powder used for .223 Rem.
Good luck with your efforts.