I was in on a cull here and took a 223 Rem with 52gr Hornady match HPs handloads pushing 3300 fps.
11 shots fired, 11 DRT deer, all adult whitetails. The 223 from what I`ve seen must be a great deer cartridge...
I took nothing over ~100yd and all were placed in the ear hole. (as best I could) I did have a stout tree branch as a rest and unspooked deer for the most part.
What I`m saying is shot placement is everything, especially with marginal cartridges and bullets. What works well when everything is right might be a whole-nutter ball game if things aren`t perfect.
JMO.........
BTW there were no exit wounds we noticed although afew had an eye popped out.