Humans just don't kill that easily. We can take a lot of damage outside of a few critical spots on the body. It has less to do with the specific cartridge and more to do with finding those spots.
Give a look at the .45 Winchester Magnum carbine, developed by 3-Ten corporation.
The president of that company just got a rejection letter from Picatinny Arsenal. Reason for rejection: the round is not a "type classified caliber."
Now, tell me if Picatinny is taking care of the soldiers.
Try giving a look at www.3-ten.com
I would carry the 3-ten.
Regards,
Ernesto