If you can shoot a heavy enough bullet out of the 45 to get consistent exits, the larger diameter 45 bullet will create a larger wound channel and has the speed advantage Max cited which further puts the favor towards the 45.
The 44 is a good round, the 45 is simply better. Same as the 475 trumps the 45, and the 50/500 is the king. If you can handle the recoil, the bigger guns are decisively better tools for the biggest toughest game.
