I just went by the Nosler load book when I worked up his load for him.

I went with IMR 4350

Min - 59.0gr @ 3051fps (most accurate load tested in the book)
Max - 63.0gr @ 3294fps (load I used in my buddies Weatherby)

Winchester cases
Win WLRM primer

Shoots nice lil clovers at 100.

If I was you I would start at 61grs and work up to the max of 63grs, I load for a few other short mags and some of them can't reach max load without some pressure signs.