I’ve killed coyotes, hogs, and whitetail using a few different rifles chambered in .223. I’ve only ever had one issue and it wasn’t a terminal ballistics problem per say.
I shot a doe down in Albany, Texas one year and she didn’t drop right on the spot which was unusual. Anyways I came out of the stand in search of a blood trail thinking it was gonna be quick and easy do to the snow fall. Didn’t find a single drop of blood not one smudge. So it took me a hot minute to find her. It was snowing pretty hard for Texas, but I eventually found her.
She died about 10 yards from where I shot her and fell into a huge pile of snow. The snow fall covered her pretty quick, the fatal shot was right in the heart but oddly enough no blood at all. When we cleaned her out internally she was filled with blood.
I always attributed it to the small bullet diameter but who knows. Definitely can take down some game or predators/varmits with that caliber no problem.