I've settled on 28.4 grains of H335 with 123 Hornady SSTs. I get 2450 fps, excellent accuracy and consistency with both of my ARs - a 22" Faxon barrel target set up and a 16" Faxon barrel hunting rig ( looks like 20 fps slower in the 16")
I've tried CFE223, VVN133, H322 and one or two others I can't think of right now, but I stopped looking after I tried this recipe. I took a WT doe, and my son took a WT buck with the 16" gun this year. Lots of fun hunting with the AR and the bullets sure killed them, but I might try the 92g Power Hunters from Hammer Bullets or the 99g Hammer Hunters for next year.
You won't be dissapointed with this fun little cartridge!