Any Ideas on why my 7-300WSM will shoot a 1 hole group at 200 yards and a 1/2" group at 400yds (both 3 shot groups) and a 5 shot group measuring under 1 1/4" at 500yds but only with new brass, can not get it to duplicate this accuracy with fired brass.
Norma brass 300WSM necked down to 7mm
necks turned for .313 chamber
Loaders-loft, seems to be dead on with the speed analogy so far! Shot today at 100yds with some promising loads 4 tenths of a grain more powder seems to be the magic load in fired cases, 3 shot group measuring .194, now have to confirm at 500yds. Thanks for the help loaders-loft