Size wont matter when you get a few freebies
If he has a gun and you have a _________ but does not know your their, but you HAVE to stop him for someone else's protection. You should take ______ (fork, knife, letter opener, bat, improvised club, brick, paper weight etc) and visit upon him (in the softest spot closest to the spine) strikes with such force and repetition that they drop said gun allowing you & other victum time to grab his gun and run away with you.
I have always thought of the "protect my self and others" as every lawful citizens responsibility against villains and criminals but I am sure someone can justify the run away and eventual call the cops look at things too.
If you are Always looking at the big picture, you are Never concentrating on your front sight post.