Posted by scrubcedar: No I was not saying to try for that precise of a target on a running human. That's not how most muggers etc. operate. They threaten you from a set distance to get you to hand over your valuables.
If he has a "short range weapon '(knife, club metal bar etc.)' ", he will have to be quite close to you to credibly pose an imminent threat of death or serious injury. So close that when you start to draw, he will most likely close the distance very quickly indeed.
And if he does not try to do so, you will have a very hard time justifying pulling the trigger.
Have you considered taking some training?