My experience with the 44mag is its a slow death.  Shot one with my lever at 20 yards perfect heart/lung.  Still ran 300-400 yards.  Not much blood trail either... 
I work with a guy that killed a nice 10pt this past season with his Marlin 44Mag lever action.  He said it stumbled about 4 feet and fell over dead.  He texted pictures from the kill site.