I finally got some data to go on
HR 22" 357 max, 25gr RE 7, Horn 180 XTP -- 1850 fps
that is barely more ME than the factory 357 mags get me. So its back to the books on this project, which is a good thing. I need a science project for the winter months. I was hoping the RE 7 would do well because I am happy with it in my 45/70 and like to minimize the cans of powder I have to keep track of.
Im getting a 44mag soon and may stretch it to a 445sm so I will look for a powder that will be a good option for both the 357max and the 44 mag/sm.
one note however, the RE7 was very consistent for velocities in the maximum.