IOWA CITY, Iowa - The rapid-fire shooting that killed or injured hundreds of concertgoers in Las Vegas has highlighted the easy availability of ammunition magazines that allow shooters to fire dozens of shots without having to reload.

  

Gun-control advocates say magazines that can store and feed 30, 50 or even 100 bullets into firearms increase the potential carnage of an attack.

  

It's believed that millions of such accessories are legally owned in the U.S. - prized by gun enthusiasts for recreational shooting and self-defense.

  

The U.S. Supreme Court is considering whether to take a case that revolves around the issue and asks if the Second Amendment gives people a right to possess the high-capacity ammunition magazines.

  

So far, eight states have passed laws restricting magazine capacity to 10 or 15 bullets.