That's right; Rainier specifically states this:

"Q6. What if I can't find load data for your bullets?

A. If you have a load for a cast lead bullet, that will transfer across the board as far as our bullets go. We recommend a starting powder charge directly between the listed minimum and maximum load."

If you haven't already got one, pick up a Lee Factory Crimp Die. You will be very pleased with the results when used with plated bullets.