According to my research a 1 in 12 is good for bullets up to 85 grains at 6mmBR velocities. Is this true? Will a 1 in 12 shooting 75 gr bullets maintain their accuracy out to 600 yds for a groundhog shoot, or should I really be shooting a heavier bullet to reamain competitive and buck the wind? I had planned on this gun for hunting groundhogs. Where I live a 300 yard shot is a long one, hence the 75 grainers.