Yeah, you're about 10 grains under max which isn't a good idea with such a slow powder. If you want a reduced load for some reason (less recoil, etc) use a faster powder like H1000. Otherwise add about 5 grains to your load at a minimum and work up from there.
Had the same problem with my 300 RUM. Problem solved by adding more powder. You could also increase the neck tension, seat the bullet deaper maybe use a hotter primer. But first choice is more powder.