23.2 of H-335 gives me 2949 fps average and a high of 3041 fps. This is the most accurate load I have tried in my Mini 14 Target model that is chambered for 223 Rem. and has a 1:9 twist and 22" barrel.
24.0 grains of H-335 gives 3011 fps average and 3106 fps high. This load doesn't group as well as the lighter one.
I use a berrys/hornady 55 fmjbt and mixed brass. Other people with shorter, 5.56 chambered, AR15's report lower velocities than what I got as well.
He who dies with the most tools/toys wins