As long as it's the XTP Mag, it will certainly work.
In my own Freedom Arms .454, with 10" barrel, I shoot the XTP Mag. in 240 gr., ahead of 20 gr. of HS-6. MV is 1650 fps. I used it last month to take a wild hog and a red deer, both shots were pass throughs and quick kills. For Whitetail, you don't need 300 gr. bullets and max powder loads of any kind out of the .454 Casull- I like the lighter bullets, pushed faster for flatter trajectory and less recoil.
