I agree with Paul S... use Hodgdon's H-110 for maximum loads in a .44 magnum.
One "CAUTION" concerning H-110, however... and this comes direct from the Hodgdon people themselves in the Hodgdon Basic Reloaders Manual 2003.
"DO NOT REDUCE H-110 LOADS BY MORE THAN 3%" (below the maximum load to determine starting load... sic).
"MAXIMUM LOAD" of H-110 in a .44 magnum (rifle or pistol) is 24.0 grains with a 240 grain Nosler hollow point bullet. 3% of .24.0 grains = .72 grains.
Therefore, a "STARTING LOAD" of H-110 in a .44 magnum is 23.3 grains. (24.0 - .72 = 23.28 or 23.3 grains)
Hodgdon's Basic Reloading Manual 2003 has the following velocity & chamber pressure listed for MAXIMUM LOADS (24.0 grains of H-110) listed for rifle & pistol using a 240 grain Nosler jacketed hollow-point bullet. This load uses Winchester cases and Remington 2½ primers:
Rifle-20" barrel:
1817 fps - pressure=36,200 CUP
Pistol-8.275" barrel:
1522 fps - pressure=36,200 CUP
I hope this information is helpful to you. :-)
Strength & Honor...
Ron T.