Re: using factory brass ?
Win, Rem/UMC, Lapua, Hornady/Frontier, BH are all quite adequate. LC and IMI military brass is good too, and should be considered to have less internal capacity, and therefore eligible and advisible for decreasing starting charge weights. Fed/USA may also be good, but over the past few years the primer pockets have been considered rather soft, rendering excessive pocket expansion when using stiffer loads. Once fired military brass has the strong possibility of having been fired in chambers with excessive headspace (machine guns, where headspace is left deliberately sloppy to prevent case extraction problems), and must be checked for interior precursor grooves that herald impending case head separations. Any brass, commercial or military, with such grooves is good only as scrap.
Greg