ORIGINAL: Paul L Mohr
Actually the 45 doesn't have that great of one shot stopping abitlity either. It really depends on the ammo you use. Quality 9 mm ammo verses 45 ball ammo I'll pick the 9 any day. If you were really worried about it you would use a .357, it has the best reccord for one shot stops.
the reason there is so much of difference is becuase you're comparing QUALITY 9 ammo and BALL .45 ammo. if you compared quality self defence ammo for both or ball ammo for both the .45 would win in either case except when it comes to magazine capacity.