If you have 700x about 5 grains with a 240 should work for you, but with large flakes it does not always throw well out of all powder measures. So try it first to see if your throw is consistent.

“To expect defeat is nine-tenths of defeat itself. It becomes a self-fulfilling prophecy. It is best to plan for all eventualities then believe in success, and only cross the failure bridge if you come to it."
Francis Marion - The Swamp Fox