I have a new Remington 700 SPS Varmint .308 , 26" bull barrell with a 12" twist. I've changed the stock to a wooden thumb hole stock and had the barrell floated and I still can't seem to get as good of a grouping as I want. I am searching for the best reload to pursue. Can anyone suggest a weight of bullet and type of powder they have good results with? I've been using H4895, and tried Sierra match kings 168 gr, Speer straight tail 165gr SP. The match kings were better. I've shot some factory loads of 150 gr Remington and Winchester and they produce the worst groupings. Which barrell twist is better for lighter and heavier bullets. Thanks to anyone for any advice they might have.