Here's a couple of loads that my 223's like. NOTE _ the 78 is almost worn out. I can't believe it still shoots OK:

223 Remington Seven, 40 grain Nosler BT, 7 ½ BR, 22.3 grains TAC, 0.44 MOA
223 Remington Seven, 55 grain Rem HP, WSR, 26.5 grains H335, .5 MOA

223 Remington Sport 78, 55 grain Nosler BT, 7 ½ BR, 26 grains H335, 0.47 MOA
223 Remington Sport 78, 55 grain Rem HP, 7 ½ BR, 26.5 Grains H335, 0.49 MOA

I prefer classic.
Semper Fi
I used to run with the hare. Now I'm envious of the tortoise and I do my own stunts but rarely intentionally