An American Special Forces commando in Vietnam with his AR-15, 1963: AP

In 1962, the Pentagon had a pickle on its hands: America wanted to give South Vietnam guns with which to kill its Communist brothers and sisters in North Vietnam, but we couldn’t figure out which guns. The answer became as clear 50 years ago as it is today: The AR-15 is an incredibly good tool for killing lots of other humans.

Update: This article originally stated that, as was first reported, Orlando shooter Omar Mateen used an AR-15 in his gay nightclub massacre. In fact, it was a Sig Sauer MCX, a rifle much like the AR-15 in both design and origin: The killing of other people in the context of war. As Mother Jones has pointed out, the MCX was developed at the behest of American special forces for warfare conditions, much like the AR-15 at the dawn of the Vietnam War. The differences are academic. Both rifles are entirely legal to purchase, and are excellent tools for murder. No one should be able to get their hands on either.

The AR-15 rifle, now manufactured by a variety of firms and available in automatic or (more common) semi-auto variants, has become one of the most widely owned weapons in the United States (the NRA boasts that it’s “America’s most popular rifle”). Not coincidentally whatsoever, the AR-15 has also become the weapon of choice for Americans who want to murder other Americans in large numbers, as was the case in the massacres at Sandy Hook Elementary School, a movie theater in Aurora, Colorado, and an office party in San Bernardino.

The gun lobby (backed by sympathetic legislators) has been quick to say the AR-15 is scapegoated, a victim of its own success. The NRA eagerly points out that it comes “in all different types of colors and patterns” and that it may have a variety of perfectly safe and legitimate non-murder uses. In 2013, former NRA President David Keene said it was a smear to call the AR-15 an instrument of war, when in fact these are “firearms that are designed and built not for the military, but for the civilian market”:

AR 15s are good for hunting. Some buy an AR for home defense and about six percent of buyers are either collectors or varmint hunters. The standard AR is illegal in most states for deer and big game hunting because it is not considered powerful enough to reliably put down deer-sized or larger game, but is used for coyote, wolf and feral pig hunting in many states.

But the fact that the AR-15 is on the civilian market simply means that a military weapon is being routinely sold to civilians. It doesn’t change the nature of the product: The AR-15 is a weapon explicitly designed for the purpose of accurately killing other people, potentially at great distances.

We know this because the U.S. military spent a long time studying and detailing just how effective the AR-15 is at warfare. Whether or not some AR-15s end up in use by “varmint hunters,” the unimpeachable truth is that these guns were invented and built to do the job of killing human beings.

In the early ’60s, the Defense Documentation Center for Scientific and Technical Research (now the Defense Technical Information Center) released a 55-page study on the AR-15's suitability for the South Vietnamese army. “The AR-15 Armalite rifle has been subjected to a comprehensive field evaluation under combat conditions in Vietnam,” the report began. It went on: “because of the controversy which has surrounded this weapon, particular care was exercised to insure that the tests were objective, thorough and adequately documented, and to insure that valid data and conclusions were derived therefrom.”

The results, culled from evaluations by American “advisors” and South Vietnamese already deployed against the Viet Cong, were crystalline: “The lethality of the AR-IS and its reliability record were particularly impressive.”

The report describes, with grisly detail, how the AR-15, chambered with the same .223 ammunition that it uses today, not only killed VC soldiers but decapitated and dismembered them:

VC soldiers shot with the AR-15 were regularly described as looking as if they had “exploded”:

Another report notes that among five VC soldiers shot and killed by an AR-15 in one engagement, “four were probably killing wounds with any weapon listed, but the fifth was essentially a flesh wound. The AR-15 made it a fatal wound.” Another field report describes how an AR-15 shot “exploded” one man’s head and turned another person’s torso into “one big hole.”



A member of the Airborne Brigade lauded the rifle’s “excellent killing or stopping power.”

The AR-15 proved remarkably durable during jungle warfare conditions:

It inspired awe and respect among soldiers for its capacity to kill:

It could even shoot through dense jungle underbrush:

In The Gun, C.J. Chivers’ Pulitzer-winning history of the AK-47, he describes the AR-15 as “an American shift in rifles for killing men,” and recounts the thousands of Pentagon tests with live animals and cadavers that charted just how well the rifle could blow through internal organs and turn brains into mist on the battlefield.

This is the genetic makeup of the AR-15: It’s not a household tool for hunting feral pigs. Nor is it meant for defending yourself against against a home invasion, unless of course a platoon of Viet Cong is invading your home. And although the early AR-15 proved to be mechanically unreliable in Vietnam, its raw killing power, its ability to blow holes through people, is just as clear inside a gay bar in 2016 as it was in a jungle in 1962.

Gun advocates will tell you the AR-15 is a peacetime weapon that should remain legal and subject to as few regulatory obstacles as possible, but they’d never say the same thing about a cluster bomb or rocket launcher. And why not? Surely both could be used for self-defense or hunting (and with automatic barbecuing!) just as easily as they could be used to slaughter enemy combatants.

But the AR-15 is slippery—it’s much more easily disappeared from the context of pure violence by NRA sleight of hand than the other instruments we associate with war. The civilian models, in deference to the few effective gun control laws we still have, are modified from their military counterparts by being unable to spray fully automatic gunfire. But the underlying machinery, used semiautomatically by lone gunmen, has done to dozens of American civilians at a time exactly what it did to the Viet Cong.

In mass shootings across the United States, the AR-15 has performed exactly as it was built to perform. It made lethal intent into lethal results, killing and maiming human targets with efficiency and ease. It was an instrument of war, and it turned a nightclub into a war zone. Wherever we allow the gun to go, that war will go on.