Retumbo for 240gr SMKs in .300 Win Mag?

I'm starting to feed the beast that is reloading .300 Winchester Magnum and was going to mess around with 240gr SMKs I had gotten for .300 Blackout. I can't find much in the way of load data for the Win Mag for this projectile. I grabbed a jar of Retumbo (because the store hadn't raised the price on it yet) and did some extrapolation from the data on Hodgdon's website. Results were pretty good: all of my facial features are intact (some might argue that's not entirely positive), but I'd like to get "on book" if I can before I start load development in earnest.

Are there any resources that include both 240gr SMKs and Retumbo? I also have a big jug of H1000 I could use instead.

You could call Sierra, and talk with a ballistic technicians. Looking at Hodgdon, web site the only have a loading for the 230gr. Berger bullets.