I've used 223 on deer quite a bit , never used a dedicated deer bullet. Mostly 50 gr Vmax over benchmark. Also started my daughters out with an AR and that load . In my experience from 20 to a bit less than 300 yds it's a good round. Bullet placement through the lungs/heart or obviously head / neck shots give pretty good results. I've shot around 25-30 deer with it and haven't lost any or had any long tracking jobs. If I were using it as a dedicated deer gun I probably would pick a tougher bullet like the 64 gr or various other bullets . Good luck , just remember they won't leave a blood trail like a .30.
