did you ever have someone 10 feet away from you trying to jump you with a knife??????
there is no time to reload or do anything. you act fast or you are done. no need for extra ammo.
and Murphys law is the reason why revolvers are better.
stop trying to prove a stupid and pointless point. Extra Ammo is useless during self defense.
Oh because you're 100% positive you're going to engage one bad guy at 10 feet??
Why do you care if someone carries a spare mag? I don't care that you think you'll only use your gun on one guy inside of 10 feet.