I agree. All you really need is one bullet. Shoot one moron and point your weapon at anybody else who still shows interest. The store would be cleared of “gangstas” in about 10 seconds.
Well then, I guess I'm uber-prepared ;o)
I'm an old guy. A group of young, fit thugs would have little problem beating me to death ("disparity of force"), unless I use a weapon to even things out.
In a situation where I have reasonable fear that I am about to be assaulted by one or more thugs, and a disparity of force exists on their part, then I have the legal right to use deadly force to terminate the threat. In the case of a hostile mob, this would take the form of opening fire upon any or all approaching thugs.