Pictured at left is one of the three types of guns that was used yesterday in the school shooting in Connecticut. It’s a semi-automatic .223 calibre Bushmaster rifle. It’s manufactured by Bushmaster Firearms International, a company based in Madison, North Carolina. It’s a civilian version of the U.S. military’s standard issue M-16. 

Serial killer and mass murder buffs might recognize it as the gun that was used in the Beltway Sniper attacks back in 2002. That’s where John Allen Muhammad, with the aid of a minor named Lee Boyd Malvo, killed ten people and severely injured three others in the Washington, D.C. area during a three week shooting spree in October of that year.

In the world of assault-style weapons, bullet calibre, velocity, range, firing speed and magazine capacity are the key criteria. As described in news reports, the Bushmaster has a 30-round magazine that a shooter can empty in less than a minute (the magazine is the curved part at the bottom of the gun). Once it’s empty, a shooter can simply pop in another magazine and continue firing.  The Bushmaster retails for around $2600 U.S., and it’s apparently a popular weapon with Mexican drug smugglers.

So all in all it’s a considerable step up from the single-shot muskets and rifles that were around when the right to bear arms was enshrined in the American Constitution in the late 18th century.