I like to do things "by the book" so I'm hoping to find published data for the 240 gr XTP bullet. I would think it has to be out there since the bullet is very, very popular but I haven't found it yet.
If you want "exact" you might have to go ahead and invest in the Hornady book... (there are worse ways to spend your money than building a library!
I don't see your desired combo in any of the "usual sources" I check online. Sometimes that means nothing. Other times it means there might BE a load, but perhaps it's touchy or otherwise less than ideal. For example, John Taffin suggests the XTP bullet seats deeper than others of similar size, which could cause pressure concerns. Not that I feel Taffin is one of the "ultimate" authorities, but he does raise a question.
There ARE listings for the 300 gr XTP and 2400, at about the charge level you're already loading w/ the 240, so you're probably in a safe range. But as popular as 2400 is in the .44 Mag, I'm left curious why there are lots of powders listed for the 240 XTP but 2400 doesn't seem to be among them.
I'll be interested in seeing what else you might find. I like XTPs, and have enough 296 to make 'em go for a little while longer, but a buddy just picked up 8 lbs of 2400, so I often share "new" recipes w/ him...