Originally Posted by etisll40
With the magnum's and an stw, the faster speeds reduces the need for lower twist. That's what a custom bullet maker told me anyway. 1-9 in the stw is all you'll need.
Just to be sure i called Sierra. Good folks too! He did some calculations and theses are his words "A 180 gr bullet in the stw is a very good choice. The velocities are what makes this bullet work in a 9 twist. Typically anything with less velocity in .284 should not be attempted. The stw tho is perfect. The bullet needs the extra velocity which will stabilize it. The 9 twist will allow the bullet immediately stabilize.
Then he said...you're at a ballistic peak given the caliber, twist and bullet weight. Once you find the favorite load, youll be amazed.