H110 or W296 same powder. these have been the goto powders for these cartridges since the beginning.
My standard Load for .44 Magnum Rifle and Heavy Pistol loads is 23 gr of H110 with a Lyman/Thompson SWC 429244 GC
Midrange loads for those two cartridges consist of a Keith Boolit 429421 with 6.0g r of W231, for the Special and 8.0 gr of W231 for the Magnum cases. This serves most uses with pistols.
Randy