Did you ever hear of a failure to stop? One of the living dead, who at the time, is on alcohol, several designer drugs, and a wicked mindset that takes 20-30 rounds to bring down and yes that includes the larger handgun calibers? Failure to stop is not caliber dependent and when one of these guys is thrashing about a head shot is easier said than done. Don't kid yourself into a false sense of security that 1, 2, or 3 rounds will do the job every time in today's troubled world. Also more and more bad guys work in multiples and teams. The "knockout king game" is a prime example of this. So that is why we carry lots of ammo. While on duty I always carried 2 spare magazines. Now retired I do the same daily with out fail. If it is worth carrying a gun, it is well worth it to have ammo for it. Bill