Pioneer.
In a war, I don't think wepick a cartridge for it's ability to make an ethical quick kill. Shoot a guy in thevitals with a 223 or 30-06 and he's out of the game. In fact if he's still alive, well now we've taken a few people out of the action. The guy who got shot, the guy dragging him to safety and the guy trying to patch him up in the field.
Not to sound cold but 223 or 300winmag. I'm not caring if he dies quickly or dies later in the triage.

All that aside. I think a 223 or 22-250 at reasonable range is fine for deer. I was just making the point that in war we are looking for something different than when we hunt.