If you haven't looked at Reloader's Nest before, you might take a look at the recipes and accuracies for Varget in those calibers and compare it to the max loads at Hodgdons data site; lots of combinations of bullets and powders. I have found some hints on some winners there, but I still work up the loads. I look for the ones with published 3-shot accuracies.
Varget is supposed to be a winner in 1:12 223's and was adequate but not the best in my 1:9 223.