As a teenager I used a 12 ga shotgun slug. Effective out to 50 yards, partly because of trajectory and partly because you can't see further than that in my woods. Every deer I ever shot dropped in his tracks.
When handguns became legal I started with a .357. The first deer I shot ran and I had to track him. It was a 25 yard shot. The deer succumbed for sure, but not before he ran 100 yards.
Switched to a Blackhawk .45 Colt with Ruger only loads. Now he only ran 20 yards. Then a .41 Magnum S&W and the drop was shorter yet. Now I shoot a .308 Winchester thru a Thompson Encore and I'm back to my shotgun experience.
Unless you have Elmer Keith's proficiency, you need a bigger gun. And, of course, that's just my opinion.