In reality, you can carry 100 rounds on you, but you will never get a chance to use more than a few.
That's the one line that should settle this debate.
D
) Carry as many rounds as you can fire in the amount of time you expect to remain alive while in "imminent bodily peril." If you can truly empty or reload those two extra magazines in the five or fewer seconds max you would be actually aiming at something, by all means carry them. But as civvies we aren't allowed to use suppressive fire, and it's comical to think you'd have time to fire many rounds at all at an attacker who is, by definition of "self defense," actively engaged in your destruction simultaneously.
I ran the numbers once for one and two attackers shooting back at the same rate and with the same skill as the victim. I assumed two hits were necessary for each part to be out of the fight. IIRC, survival odds were 70% after the first round, ~20% the second, <5% after the third exchange of bullets, and 2% after that (by the fourth volley, if the shooter was still alive, odds were the second attacker was no more and the odds loss flattened out as the fight became "fairer.")
Odds were infinitesimal that the fight would continue after 6 volleys (both for needing that round to stop an attacker who himself only had a 10% chance of survival, and for the defender still surviving). The biggest factor in survival, btw, was accuracy percentage, not hit rate. It's possible to be twice as accurate as someone, another to pull the trigger twice as fast as him and still shoot as effectively. With twice the chance of a hit as the bad guys, the odds were closer to 50% survival after the second volley. Practice is a good thing
Oh, yeah, with even three attackers, odds of survival went something like 10, 2, >0. If you survive an encounter with three shooters, it's
they who did something wrong, not you who did something right
It was a fun math/game theory experiment, and one who's conclusions were even more obvious than I expected them to be; a gunfight only lasts a few seconds (even if interrupted), chance of survival is slim but higher than if you were unarmed, and is hugely stacked in the bad guy's favor because he will probably get to shoot first if he gets to shoot at all (and the fight is on his turf, on his time table, etc.). No matter how I played with the figures, odds of survival dropped rapidly until only one attacker remained, and odds of survival were tiny after a half dozen rounds (unless I dropped hit % to around 10% for all involved
). Any advantage in (effective) rate of fire or accuracy over the attackers had a magnified effect, and the opposite even more so. We'd better hope we're never mugged by Jason Bourne and Leon the Professional
TCB