I started with Magpro,others said that powder was made for the WSM's . Started with 64grs and got high of 2,918 and a low of 2898 . I stopped at 67.0 grs High of 3,056 ,low 2,990 . All loads shot poorly at 100yds. I know I have a 9"twist bbl. Anyhow I'll be putting the Magpro back on the shelf .