I actually wouldn't consider a head or neck shot ethical, especially with small caliber rifles. So to each his own I guess.

I my opinion anything that will poke a hole in the lungs of a deer will kill it and is ethical. What it boils down to is knowing your weapon and what it's limitations are. I don't believe there is a center fire rifle made that isn't capable of taking deer sized game as long as you have the proper bullet for the job and keeping range and shot placement in mind when hunting.

Ethics has absolutely nothing to do with whether a certain weapon will kill deer or not, it has to do with what you personally feel will work in your situation. Some people have no qualms about killing them with a bow and an arrow, others feel they need a 7mm mag or 300 win mag. Both will give you dead in under 10 minutes if you know what you are doing.

I have killed injured deer on the side of the road with a hunting knife before, they are not mythical creatures that require weapons with special powers to kill them. Put a hole in the lungs and/or heart and they expire in short order.

My opinion anyway.

Paul