i have a husky 'sposed to be 12.7x44 that has had some kinda .50 cal. reamer took to it. i use 05-70 starline brass, 450 gr. boolits, 2 milk carton wads, and 60grs. goex 2f. no sizing required in my gun. compress powder and hand seat boolits. 2 to 3 in. groups @ 50 yds. which is about all my eyes are good for anymore. don't know if this helps but, works for me. as you will no doubt discover, all these beasts are unique. just find what works for you and let'er roll.