Going to be running 300 bergers for now.
i also have some imr7828.
50 bmg does look to slow. So i might use it
in my 300 rum. Would only lose 40fps. Maybe. With 30" barrel should give it time to best use the 50 bmg powder.
i have 8 pounds of both.7828 338 and 50 for the 338.
It does help a lot. Retumbo and h1000 is what I planned on using. Both are like looking for a unicorn in kC. What I do have I use in my 300 ultra mag and my 243.
I have both the the imr7828 and imr7828ssc