I had great results with Shooters World Precision Rifle powder. Loaded in the 556 pressure range. Shot 9 shot groups, couldn\’t get 10th round in my 10 round magazine, all groups could be covered with a nickel. Speed averaged just over 2800. I didn\’t have much luck with TAC either. CFE223 did OK but not as good as Precision . I really like the powder, works great in 308 165 and 168 grain bullets too.