Don't know how you guys remember what the bullets did unless you are keeping a journal, I don't. Been hunting elk for 45 years or so and have used everything from 6mm Rem with factory 100 gr to 338 WM and everything in between. For the last twenty years have been using Barnes exclusively and a lot of times the perfectly mushroomed bullet is caught in the offside hide. A lot of times there is a hole on the opposite side, kind of depends on where the animal is hit.
The only journal that I keep is on elk, where I list the year, where I shot it, # of points or cow, and the rifle that I shot it with. Except for my first 10 years of hunting, I've pretty much stayed with the same bullet for each rifle. For example, the 21 elk that I shot with my .30 Gibbs were all shot with 180 gr Partitions, as those were the only hunting bullets that I shot in that rifle.
The partition bullets that I recovered from those elk (and moose) were all flattened back to the partition and I found them just under the hide on the off side. My conclusion there is that the large, flat mushrooomed front surface caused those bullets to expend most of their energy inside the animal, and that there wasn't enough energy left for that large,flat surface to punch through strong elastic hide of the far side of the animal.
After I built my .375 RUM and .300 Weatherby, all of the animals except two that I shot with those rifles were with Barnes bullets. Of the 30 plus of these animals, I only recovered 8 bullets. The first elk that I shot with a Barnes bullet impressed me because of the lack of bloodshot goo around the wound channel compared with the large bloodshot areas in the elk that I had previously shot with my .30 Gibbs with slower and heavier bullets. That one is also easy to remember because I took pictures of it when I skinned him.
Then, after my very nasty divorce 20 years ago where she wanted half of her very inflated value of my taxidermied animals, I've kept a computer record of all of my mounts. On that Excel spreadsheet it's easy to record the animal, the taxidermist, the year I shot it, the year it was mounted, the cost of the mount, and the rifle and bullet.
Other than they killed the animals, I mostly don't have a clue as to what the bullets did on all of the other animals that I've shot. I also usually don't spend a lot of time looking for the bullet in an animal. But those bullets that I have recovered I keep in a small box, and now I don't know what animal most of those bullets came out of.