I wouldn't worry about it, Hodgdon lists 4.0gr as a max load but just using a magnum primer shouldn't increase your pressure much, if any.
If you're worried about it drop down to 3.5 gr and shoot away. As long as your gun will fire the magnum primers (they're often harder than standard) they should work just fine for you.
If you're worried about it drop down to 3.5 gr and shoot away. As long as your gun will fire the magnum primers (they're often harder than standard) they should work just fine for you.