Thread: 223 on deer

I was never very impressed when I had a 223. With 60 grn factory stuff it lacked penetration. The last deer I shot with it was a pretty ordinary sized 2yr velvet stag. Shot just forward of the base of the neck, bullet hit the vertibrae but didnt have the momentum to break it. So the deer was laying paralysed but fully alive blinking when I got to it.
Fast forward, hunting mate has bought a 223 for fallow and reds paddock shooting. Is there a copper bullet that I could reload for him that kills really well ?
I would like to go copper / lead free