I believe that over 90% of encounters where a gun gets pulled ends with no shots being fired when the bad guy changes his mind when he sees the gun. In that case, an unloaded gun is as good as a loaded gun as long as you are a good actor.
According to DOJ crime statitistics, guns are used by private citizens 2.5 million times per year to prevent violent crimes like rape, robbery, carjacking and home-invasion, 99% of the time without a shot being fired. (Source: GunFacts.info)