Kdiver, I think you have a point with your first post. Their response is generic and really doesn't even address the real issue, they have no data for a magnum pistol cartridge using their own powder.
Condescending previous comments aside, and there were several, it's fine for a company to have limited data, they just need to respond effectively.
Example: My office manages the fish populations in area lakes. We don't manage the parks around them. Yet we get calls about park reservations and just about anything you can imagine. My crew members COULD respond like the gentleman from Alliant, OR they can be helpful. "I'm sorry, we don't manage the parks around Lake X, but these people do and here is their number." Or "I'm sorry, we don't regulate the duck hunting at Lake Y, but these people do, the drawing is in August, and the website is . . .".
So in the case of Alliant, "I'm sorry, that is a relatively new powder and we haven't developed loads for every cartridge. While we haven't tested loads and can't tell you what is safe and what is not for that cartridge, you could check with your bullet manufacturer to see if they have data"
This is the minimum I would expect. They are a Customer Service rep after all.