Today a gunman at Sandy Hook Elementary School allegedly used a .223 caliber rifle to kill at least 27 people, including many children. The video below, courtesy of YouTube user KENFL74, shows a Bushmaster AR-15 shooting .223 ammunition. Many different kinds of guns use this caliber, of course; this is just one example. CNN, however, reports that a .223 Bushmaster was found on the scene. Guns and Ammo has made the case for why AR-15 guns are ideal "home defense" weapons, saying that military-style guns like the AR-15 have always been popular in the U.S. The guns are certainly popular on YouTube, where children of various ages can be seen firing them. For more information on the shooting in Newtown, Connecticut, see the Atlantic Wire's live updates.
Update 9:50am, December 17, 2012: The New York Times reports that Adam Lanza used a .223 caliber AR-15 style rifle manufactured by Bushmaster to kill students and teachers at Sandy Hook Elementary School.