This is an interesting dialog; however, I am not seeing two very important elements being addressed: the duty to retreat and the doctrine of equal force.

Does the jurisdiction where you are contemplating using a warning shot require the potential victim retreat before using lethal force? If it does, and you (claiming fear for your life) are engaging the "perceived" threat, you have obliterated your legal defense!

Does the jurisdiction where you are contemplating using a warning shot utilize a doctrine of equal force? In some jurisdictions, you may engage a perceived threat only with a level of force that is less than or equal to the level of force that is employed against you! In many respects, you must perceive your life to be in immanent and immediate danger in order to justify lethal force in order to neutralize a threat against yourself or another.

There is much more that needs to be taken into consideration when contemplating the use of deadly force in order to protect yourself or another than just being armed!

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Judge control not gun control!