I would probably purchase ADG Brass, current manufacture winchester fodder is CRAP, I rejected about 25% of two bags a couple years ago due to shitty quality control split necks, dimples/creases just plain shit. The ADG (Alpha Development Group ) Brass was extremely consistent weight wise across the whole lot, I think, IIRC 3.5 grains total spread between heaviest and lightest in 100 weighed. Don't have experience with hornady 300 WM brass. Old blue and white bag WW brass got me to beyond 1K, back when winchester cared about quality control.