Large capacity magazines are for those people who are lousy shots. If you are well practiced, calm and steady then one round should do the trick, but that has nothing to do with the topic. The topic is totalitarianism and the liberal agenda to control what you own and possess. There should be no restrictions on what you may own and use. If someone wants a 30 round magazine then it is not the government’s business to interfere.
And people who have lots of targets...
Last time I checked, you ca take your rifle out deer hunting with a 30-round magazine (full) here if you want to.
If you exceed your bag limit, that's a no-no. If you need more than the first couple of shots to fill it (whitetail deer), you should practice more.