. Anyone who shoots knows that with a little practice it takes only a few seconds (some can do it is less than one second with some guns) to change magazines, so there is little to no difference between having three 10-round magazines or one 30-round magazine.
I'm sorta skeptical of this. I know it's fun to imagine being some sort of well-honed shooting machine slapping in one clip after another, and you can probably achieve that on the target range.
But, Mr Psycho flipping out in the middle of a room of screaming people? I'd say the more actions he has to take to kill people, the better the chance of fumbling or slipping up or something jamming.
So it won't save everyone in such a situation, but maybe a few? And that would be worth the inconvenience of not being able to have your big impressive action-movie (dakka dakka dakka) magazine.