Wild bill good thought. If I may expand on your thought.
One should use the weapon which you are most competent and sure of.
For that reason, when it comes to a serious social occasion I default to my 1911 government model. It is old and ugly but I am confident I will put that big bullet on target and the slug will do its job.
If one is more confident with a shotgun or M-4 than a pistol, they should opt for those weapons in a serious encounter.