I'm getting tired of people saying that outlawing large capacity magazines would somehow make us safer.
I own a 9mm Glock semiautomatic pistol just like the one used in the recent Tucson shooting. I use 10 and 15 round mags, because I can drop an empty mag, insert a full one, and start firing again, all in less than 3 seconds. I know this because I have done it over and over again. It's easy, I don't even train. Anyone can do this.
Here's my rig with the 15 round mag: http://bparkinson.blogspot.com/2009/09/self-defense.html
Smaller mags are actually MORE lethal, because the gun is so unbalanced by the outrageous weight of 33 rounds in the large mags. Use that mag and you will shoot high. If Loughner had used the mags designed for his weapon, he would arguably have killed and wounded more people.
You don't see professional soldiers putting these big mags in their pistols for just this reason.
I do want the 33 round mags to put in my Kel-Tec Sub 2000 carbine though. Its a perfect magazine for that application.
The left have this one wrong. I admire their intent, but they're focused on the wrong thing. The answer is to make it much harder to buy a handgun. I bought a pistol in Idaho simply by showing a drivers license, as if that demonstrated anything about my suitability to have weapons. Insane.
But Idaho is a pretty primitive place, after all.