Sure, the chances of it happening are slim—until it happens. And you have satisfied the #1 rule of gun fights.
So you pull out your Ruger LCP .380, fumble racking the slide while his finger is on the trigger, and the bad guy has a .45 ‘hand cannon’.
The police report says you both had guns. The bad guy is gone. You’re dead.
The other guy already has a finger on the trigger. So you pull out your supergun - and he shoots you in the face while you are clearing leather. It will take him 1/4 second to pull the trigger and shoot you, so unless you have an incredibly fast draw...
And no matter what pistol cartridge you shoot him with, after using your super fast draw, unless you shoot him in the brain, he WILL have time to empty his 45 into you before he dies. So you will then die about 5 seconds after he does.
Might want to rethink your plan of action.