I've been reloading for over 25 years an in all that time I have never had a cartridge that is so picky to load for!! Maybe its the platform I'm loading for (AR15) but no matter what I do you can forget repeatable performance ! Exact same loads will not print the same! Groups right! Same load will do 1-1.5" then reload same every thing and get 2-2.5" ! Get a good group at 2800 fps add.2-.3 of a grain and get a 4" group! So now I'm finding the one load that works most of the time and forgeting trying to improve on it! Looks like either H4895 or IMR4895 are the powders, Varget worked with nice STD but accuracy wasn't there! IMR 4064 was ok but STD was wacked and groups were so so!
And before you ask every thing was weighted, bullets ,cases,powder etc!