With hand loading, it seems the 55 grain bullets work out best for a lot of folks, no matter the twist rate. Some have had good luck with 65 grain bullets in the 1 - 9" twist. I would try one of the slower powders for the 223. H4895, Varget, WW 748 and BLC2 would be good places to start. Just remember that what works in my rifle dos not mean it will work in yours. You are going to have to pick some likely loads and work it up to find out what works for you. In my Humble opinion accuracy trumps velocity and Handis seem to do better with moderate loads. Good Luck and Good Shooting