Trying to play around with a couple 223s. One is a CZ 527 (1:9) and the other is a 18" AR that I built (1:8). With a few 68 grn that I have loaded, I have not found a rifle that likes them. Going to play around with some CFE223 and Varget. Was using 748 powder. Trying to reach out to 500 yards. I have no problem with the 18" gun and 55 grn FMJ to hit steel at 4-500 yards..