IMR 4198 generally will provide the best grouping performance in most .223 rifles. My best load in my Savage 112-V is 22 grains with any 50-55 grain bullet. There is an old saying to the effect of "if you can't get your .223 rifle to shoot well with 4198 then it won't shoot well with anything." You will have to experiment some to determine the best bullet seating depth.