assess your risk realistically
Well,
The 2.3 shots per incident is from the DOJ and that may include suicides, so the figure might be skewed lower than what really goes on. Police statistics point towards 5-6 shots before the 80's and 9-13 shots in the 90's. In other words, policemen usually emptied their revolvers (<1980) or autopistols (>1990) in a gunfight. This was an issue of Guns and Weapons for Law Enforcement.
Anyways, my point wasnt' the number of shots fired. My point is to make a realistic assessment of your risk and deal with that rather than an unrealistic scenario. If I'm going to an NRA event or a gun show, I'll carry nothing. No BG is gonna mess with that, so the risk level is zero. If I'm going to the local grocery store in the burbs, I'll carry a revolver or a derringer or a kel-tec p3AT. The risk level is very low. If I'm going to drop off the kids at school, I'll carry a revolver. Gun free zones are inherently dangerous. That's why serial killers always kill there because the citizens are helpless and defenseless there. Thank God I live in Texas. It is legal to carry a gun in your car in Texas even if you are in a gun free zone such as a school. It is legal in the parking lot. If I'm going downtown at night (which I try to avoid), I'll carry a glock 19. If you're expecting trouble, an AK47 is the only way to go. For example, your wife is in the home and as you come home, you see the door has been busted in from the outside. That's when you reach into the gun rack of your pickup and pull out the AK. If nobody's home, I'll call the cops and wait. No property is worth losing my head over.
BTW, you don't need more then 2-3 bullets per assailant if you are well trained. Yes, you will miss if you have a stressful gunfight. However, you can simulate stress in training. I am currently taking a self-defense pistol private lessons and my instructor would randomly pinch me, slap me upside the head, or hit me with his walker to simulate combat stress. I am expected to shoot accurately while being pinched, lightly punched, and smacked upside the head. I practice to ignore stress and shoot accurately despite it, thereby not wasting ammo, even while under stress.