We tried a various bullets including maxi hunters,buffalo bullets,sst,shockwave,areo tip,and barnes. It seems that all 3 rifles preferred different bullets even tho all three was exactly the same caliber(.50). Honestly,I ran out of supplies and money to buy more long before I could solve all the mysteries and it created more questions than answers. I'm sorry I couldn't be more help. I did notice that a plastic wad under the sabot helped accuracy dramatically.