First find a bullet your weapon likes. The SMKs are nice, usually not so sensative to seating depth. They do well in every rifle I use. The A-maxs have recently replaced them due to availability and similar accuracy but are cheaper.
Let me give you a direction many have nto mentioned. Check ou the new Reloader 17. It was specifically designed for short magnums like the .308. I have yet tried it but I will be giving it a shot over the Rx15. Rx15 has by far been the most accurate in all my rifles even over the Varget most the time.
Reloader 17 simply expounds on the strengths of a short magnum. people are getting the same kind of accuracy out of it that they get with popular powders such as Rx15 and Varget but with WAY more velocity. If your going to be eventually looking to getting a bullet farther down range your going to want a powder that can stay accurate but greatly increases velocity. So far the data says Rx17 will do that. Dont know what they availability is there for you tho bc its fairly new.
There some velocity discussion about it with a 190 gr bullethttp://thefiringline.com/forums/showthread.php?t=419799
Also, again, check twist rate. Though the .308 is not as senstive to twist rate and bullet weight ratio as the .223, its still a good thing to keep in mind
Havent done much with brass testing. Winchester has never failed me. Federals accuracy seems to drop significantly after 5 or 6 loads. Dont know about lapua or normas. Im too poor to find out.