My .223 (1-12 twist) Likes a mid power load, groups got loose as the power went up, this was with a few dif brands of projectiles (55 Grain), and IMR-4895
My .243 did the same, and ended up liking VARGET the best, about mid power load.
Maybe with lighter bullets it would do better pushing them a lil harder, I never seen Pressure signs with the .223, just looser groups.