I have a new M 700 Police 300 rum, I was planning on shooting 180 gr. Through it, but after reading some of these post, I'm wandering if I need to go heavier? I've got other rifles to hunt with, it will mainly be a long range toy. If I did hunt 180 gr is more than enough hunting central Texas. I got a mark 4 20x sitting. On top. So shooting at a grand which weight will I have the best luck with?