It's been kinda crazy for me. I've weighed bullets that were all over the board that grouped really well and I've have consistent weight bullets group really well. And I've had some that no matter what never shot well. The biggest secret in competition shooting is the head game. If you think it makes your groups tighter it probably will. At reasonable ranges out of hunting type rifles I've never noticed a difference. In target rifles I have noticed a difference at extended ranges. If I sort bullets then I also sort brass and turn necks the whole package seems to make a difference. All of my hunting stuff I do not waste the time.