AA1680, W296, H110 have all worked for me in sub loads. You won't have the issues of trying to make a gas gun run, so these should be easy loads to get worked up.Ordered a couple box's of 190 sub X's to try in a Savage Axis2 300blk. Trying to figure out which powders to try. I've had good luck with Accurate #9 with 220 Berrys ,so probably start there. Different forums also show people having luck with w231/hp38 and Unique as well.