As others have said, "IF the 223 is legal and you place your shots well", the 223 with proper bullets will likely work on reasonable sized deer.
The Nosler 60 grain partition and 64 grain bullets as well as the 64 grain Winchester bullets are purpose made for big game and I am sure others have suitable bullets.
That said the 6.5 Grendel will do it better as well as others, including the 7.62X39.
Course dead is dead
