Well I had about 200 pieces of federal brass I got from plinking 150 gr .308 cheap walmart stuff. Definitely seems they need more sizing per shot, even in my bolt action. I dont get the feel like they will last over 6 or 7 shots. At the 5th shot I loaded them up with a good moderately hot hunting load that average .6 MOA and plan to toss them after that use.
But for range accuracy and keeping price low I got with winchester. Ive managed .284" as a best and average between .5-.7" groups. Even on the 8th load I'm keeping them under 1 MOA. I would love to try some Lapua and some other high dollar ones but why change what works and what is cost-effective? I have yet to have issues w/ a winchester but have never had a chance to go past 9 loads.... yet.
The GMM you mentioned uses Sierre Match King Bullets, so you may want to start with those when reloading. I use those as well. They do well, along with the A-maxs.
Winchester has my vote on brass. And yes, separate by manufacture and maybe even weight as well as # of times shot.