1-9 twist, Have you tried winchester white box?
Thats what I would suggest fior factory, many mnay guys here LOVE it!!
For a handload, there are a number of good powers and bullets that work well in the 223. Personally, I'm not a big fan of the heavy weight bullets in this caliber. If I need more range I just choose a bigger caliber. So the bullets from 50-55 are what I like to shoot. H332 W/match primers are what I use.
CW