" It would be nice if Springfield made an XD 10mm"
They make a .45 ACP which is perfect for .460 Rowland conversion.
If you really want lower level revolver magnum power, do the .460 Rowland conversion, and you are getting around 1,000 ft lbs with a big bullet. Then you are getting there. For the O/P the 10mm sounds fine as he does not need serious power, 750 ft lbs would work fine.