



Since the massacre in Orlando early Sunday morning, pro-gun pundits have come out in force to argue that the weapon used in the attack is not an assault rifle. The gun lobby prefers to call these weapons “modern sporting rifles,” euphemistic ammo it can fire in an ongoing semantic debate. But make no mistake: What the Orlando attacker used was a weapon of war. It was designed to kill as many people as possible, as quickly as possible. Witness this harrowing audio captured by a bystander outside the Pulse nightclub in which Omar Mateen fires 24 shots in 9 seconds.

According to a federal law enforcement official, the rifle Mateen used to murder and maim more than 100 people was a Sig Sauer MCX. Mateen legally purchased the weapon, similar to an AR-15, on June 4 in Port St. Lucie, Florida, near where he lived. (He legally purchased a Glock 17 handgun the following day, which he also carried during the attack.)

Sig Sauer promotes the MCX as “a complete weapon system for any scenario or environment.”

Sig Sauer bills the MCX as “an innovative weapon system built around a battle-proven core.” The company says it “stands as the first rifle to be silenced from the ground up. It also accepts a broad array of accessories, enabling you to build a complete weapon system for any scenario or environment.” It has a military-spec trigger and a magazine capacity of 30 rounds. According to the book Guns of Special Forces 2001-2015 , the MCX is known in military circles as the “Black Mamba” and was developed at the request of the US Army’s special operations forces.

Although the legal civilian version of the gun fires on semi-automatic, it can be highly lethal. Indeed, like many of his recent predecessors, Mateen was able to unleash a devastating barrage of gunfire. The law enforcement official declined to comment on the total number of rounds fired in the attack. But, he said, it was “obviously a lot.”

Read our in-depth investigation of America’s 10 biggest gunmakers.