I wonder how well the 4451 would work in a 7 REM mag? I have never loaded anything but IMR 4350 in the many 7's I have owned. Reloader 22 does really well for me in my 300 Win mag. I have been threatening to try it. The young guys say IMR 4350 is an old man's powder. Hard to stop using a powder that works so well for you.
