I agree with driftrider about the twist , Also I want to add somthing I noticed this week on two different Ammo. brands of 30-06 in 150gr.
I shot 10 bulets PMPs and 10 Remengton springfileds. The PMPs grouped so good where the Rem. didn't. I found out that the Rem. projectile is longer than the PMP,and then the PMP has more thick rear part before it starts to get curved to the pointed section. To some the whole thing in two word it is the "weight distribution" of the projectile.

Hunt Safly & enjoy the sport
Toons