I mean no offense to anyone, but the heart/lungs of a deer present a dramatically larger lethal target than the spine in the neck (or the back). Of course a perfect spine hit will drop a deer instantly and a close to the spine hit will drop a deer temporarily. With more than 45 years of deer hunting experience it is, in my opinion, unethical to aim at the spine if a heart/lung shot is possible. I have NEVER met a guide or outfitter (in Iowa, Missouri, Minnesota, Colorado, Wyoming or Montana - the states in which I have hunted) who suggested a neck shot rather than a heart/lung shot. My closest hunting buddy grew up in a place where neck shots were the norm. I have helped him track his wounded neck-shot whitetails for miles without recovering them. We have hunted elk, mule deer and black bear together. He no longer aims for the neck. Check this out to evaluate lethal target areas of a deer:
http://forums.mathewsinc.com/archery...iagrams-85426/