Little help! Guys, I done some extensive testing in a new 300WSM. I tested many powders and found these three to produce sub 1 moa goups at 100 yards in 5 shot groups. My best combos on adverage were: RL19 - 67g - 3000fps H4831SC - 64g - 2850fps IMR 7828 - 66g - 2800fps My problem is Im loading and shooting now at 70 - 80 deg F. I will be hunting in -10 to 50 deg F. I need a temp stable powder. I see little difference in groups at my current temp and 200 fps difference between. What powder do I choose? Thanks!