First deer ever, way back in about '68 was with a Zouave shooting an "illegal" minie (Illinois required round balls then). Forty yards from a treestand, light snow on the ground. A four foot diameter bloody donut (with center hole) sprayed on the snow behind the deer. Dropped at the shot. I scratched around in the snow and leaves but couldn't find the slug. I'd bet it was over an inch in diameter.
Couple of deer later I had one that didn't go through (a round ball this time) and it was undere the hide on the off side, measured about an inch and had stretched the skin out enough for a eight inch diameter pool of blood under the skin.
I used to even shoot in bench rest matches with the zouave by putting a lyman aperture front and redfield rear on homemade bases. Round ball (570 dia), patched with ticking and sixty grains of FFFg. Fifty yard five bull target, often 49 with three or four Xs.