I'm certainly no continent traveling hunter but have had enormous experience with deer, and smaller stuff, in the woods of the Deep South - Georgia and a little in Va. I like two holes in my deer; don't always get them but it's what I prefer. I've hunted mostly with a couple of .45s but also with several .50s, a .54 and a .62. Up close, say under 50 yards, the entry holes (even with a .45) are, well, awesome; exit holes not so much but both do bleed copiously. On angled shots sometimes the ball simply flattens out under the off side skin. On longer shots, 75 to 100+ yards, pass through is the norm with entry and exit being some smaller. A prb is a large, soft bullet and makes a sizable hole going in. It then expands and produces impressive internal damage to the organs; that's what kills. If you shoot a deer NO energy is ever wasted; its work is done whether or not the prb exits.
One deer shot with a .50, almost broadside, ran into the bush. Since I always stay on stand for at least an hour after a shot - doing this has many times enabled me to collect a couple more deer as I did on this occasion - I happened to notice A Cardinal (the bird not the priest) perched in a tree about where the shot was taken. When I finally came down I recovered the second deer and started tracking the bigger one. The "Cardinal" turned out to be a fist size lump of lung tissue. The deer was just a few yards in the bush. Another time an 8 pt buck was quartering away at maybe 20 yards. I fired my .45 and he ran, staggering like a drunk, and I heard him crash moments later. The blood trail a little ways past where I hit him was astonishing. There was blood waist high on tree trunks and scrub. He was expired a few yards farther on. The entry hole was, again, enormous. The ball was flattened just under the offside skin.
It's the large lead ball and reasonable velocity that kills by doing internal damage. No energy is ever wasted once the deer is hit; and while two holes are preferable, just one will do the trick just fine.
