Mine shoots PRB and 425gr Hornady Great Plains conicals reasonably well with open sites, as long as I do my part.
My PBR load is 70grs (target) & 80grs (deer hunting) of goex 2f, a .015 patch, and Speer .530 RB.
My 425gr Great Plains load is 100grs of 2f, which I use for elk hunting.