3. Should it be done? The general consensus is that you need 1000 fl/lbs of energy to kill a deer. A 45 ACP is only 400-500 at the muzzle. To get to 1000 you need a hot 45 Colt or 44 mag. Now personally I like the Taylor KO factor better than pure energy calculations which shows 12.7 for the 45 vs say 6 for a 223 despite the 223 having close to 3 times the energy. However a 223 would enter, expand, and probably exit, leaving two holes for blood loss, while a 45 will probably stay in the deer leaving only one larger hole for blood loss. So while it is borderline for caliber, if you are looking for a challenge and have the marksmanship to make the shot and the discipline to not take a bad shot, it would be a nice change. But if you just want to kill a deer, take a good rifle and leave the handgun at home.