I use the same place as Snappy, but on Deer, its called the Atlas joint, and can be done with a variety of tools, including a knife if the animal isnt very active.
It may be worth getting someone to show you how to use a knife, if you are rightly concerned about a Centre fire round at close proximity. Remember there is no legal minimum calibre for human dispatch.. Yo can also use a shotgun.
Think you mean humane lolol