I have two .44 mag loads I like, neither is maxium but both will group exceptionaly well.
240 XTP over 22gr WW296, 1305 fps
290 WFP over 21.5gr WW296, 1350 fps
I would suggest you find out what load shoots the best group for your pistol as opposed to how much power you can get. Both of my loads will shoot under 1.25" at 20 yards off the bags and I can hold a 4 inch group at 60 yards off my tree stand. I tried powder/bullet weights until I found what my Super Black Hawk liked the best.
Rick