If you do a little searching on the NEF forum, you will find some places to start. For light loads, you can find data for Unique. For hunting loads, I use Varget with my 350's cast from a Lyman mold. I started at 40gr. and worked up from there....
The 405's are very forgiving, and I can load from min. to max. and still get acceptable accuracy. Most of my loads were worked up from the Lyman handbook.
Ben