I'd figure a Mozambique drill with a .41Mag would only require one round to the chest then one to the head....
Should work. Its what I do with my Single Action Army. Learned it from my Dad, he was a SAA master way before I was born. "One to the wishbone then one to the teeth" is how he describes it. He says the old 255 grain .45 Colt bullet makes a nice neat, round hole in teeth.
Those are 265 grain Keith Types over 18 grains of 2400, not a milk sop cowboy action load. The ones in the belt slide are 250 grain Gold Dots.
I really like the Tom Threepersons holster for speed with the SAA. You can cock it in the holster and get the first shot of in the .25 second range when you draw on your on volition. Of course its more of just a nostalgia toy today, but I can still draw and fire two shots from my Single Action Army than the average person can with a modern semi auto. It just takes practice.
Thats the secret, practice. Settle on a pistol, find reliable defense ammo, then practice, practice, practice. Practice presentations when you can't get to the range and always practice safety.
The 1911 will always be my favorite though. Nothing like drawing and shooting 7-9 times in less than two seconds and having them all hit COM.