I have tried many powders in the 223 but I have three that I keep going back to. My favorites in order are Benchmark (great velocities and accuracy), bluedot (ok velocity but no recoil with great accuracy) and H4895 (great accuracy but not quite as good velocities as Benchmark).
Benchmark has quickly become my favorite 223 powder as it gives me 3200 fps with 40 grainers and .5-.75 in 5 shot groups. I have gotten my very best accuarcy with Sierra 52 BTHP match and 53 HP match, .5's. Also do well with 40 Nosler BT. Primers I start with rem 7 1/2's and then experiment from there if needed. For my true accuracy loads I use cases that are weight sorted and neck turned, don't know if it really helps but it makes me feel better.