How the AR-15 Rifle Became America’s Most Dangerous Weapon

The Allen mall shooting on May 6 was the 199th mass shooting of 2023, marking the most recent incident in which a gunman chose to use an AR-15 style rifle during the tragic event.

Referred to as the “most popular rifle in America” by the National Rifle Association, it has become a staple across the nation, with many believing the AR-15 symbolizes a commitment to the Second Amendment—as evidenced by the numerous lawmakers that have sported the firearm as a pin.

Originally advertised decades ago as a sporting or hunting rifle, its reputation has largely become associated with mass shootings. At least 10 of the 17 deadliest mass shootings in America saw the gunman use an AR-15-style rifle, according to The Washington Post.

“Over time, it’s evolved from this thing that was another kind of product on the market to this sort of ubiquitous stature,” Danny Michael, the Robert W. Woodruff Curator at the Cody Firearms Museum, tells TIME.

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What is the AR-15?

The AR-15 is a semi-automatic self-loading rifle first produced in the mid-1950s. Experts vary in their description of what AR stands for (there’s discrepancy about whether it stands for the company that designed the firearm, “ArmaLite,” or if it’s in reference to the “ArmaLite rifle”), but all countered against the misconception that it stands for “assault rifle.”

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Whether the AR-15 is considered an assault weapon has become a heated debate. The National Shooting Sports Association does not classify the AR-15 as such, instead listing it as a modern sporting rifle. Experts like T. Logan Metesh, a firearms historian, tell TIME that historically, an assault rifle was defined as a fully-automatic fire rifle and that today, an assault rifle is defined as a “firearm capable of selective-fire,” which he says precludes the AR-15 from being in that category.

But Michael says the definition of an “assault weapon” is more legislative than technical, meaning the criteria varies based on the law. In states like California and under the federal government’s 1994 assault weapon ban, the AR-15 is categorized as such, per the Giffords Law Center.

ArmaLite originally marketed the AR-15 to the military, but was unsuccessful, leading the company to sell the patent to manufacturing company Colt in 1963, according to Metesh. The rifle was marketed to civilians as a hunting and sporting rifle by Colt, though the “big core concepts” that designers worked on was creating a firearm that was “lightweight and modular,” Michael says.

The M16, a military rifle used during the Vietnam War, was adapted from the AR-15. But the AR-15 differs in that it was marketed as a semi-automatic rifle, whereas the M16 can also be a fully-automatic weapon and release a burst fire.

Why is the AR-15 so popular?

The AR-15 has no doubt become a staple for gun owners, as recent estimates show that there are some 20 million of these rifles across the U.S.

Much of the popularity of the AR-15, which one expert describes as a Lego set, is due to its modularity. “It’s gotten to the point today where the design has a lot of refinement to it, so pretty much any feature of the rifle is configurable to some degree,” Michael tells TIME.

Others say that price definitely plays a key role in its high demand. The cost of an AR-15 varies depending on quality, but they are typically priced at $400 and up. That’s not to say that an AR-15 cannot cost thousands, but by comparison, a pistol may cost around the same price despite its much smaller size and capacity.

Metesh also attributes part of its rise in popularity to the boom of sales seen once the patent for the gun expired in the 1970s. “Once Colt no longer held the exclusive rights to manufacture AR-style firearms in the United States, dozens of other companies jumped at the opportunity to start making and selling these rifles to the public,” Metesh says.

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Is the AR-15 the leading firearm used in mass shootings?

Steve Lindley, program manager of Brady United Against Gun Violence, a gun violence prevention organization, says he would hesitate to call the AR-15 the “weapon of choice for mass shooters,” but still describes the AR-15 as a “weapon of war.”

That does not deflect from the fact that mass shooters often utilize an AR-15, likely for the factors mentioned above.

Besides the Las Vegas shooting, which was carried out from a long distance, “mass shootings are relatively close up,” Lindley says. He says the AR-15 has such a strong capacity that gunmen “don’t really need to aim, they just need to shoot at the crowd of people.”

Have there been any attempts to ban the AR-15?

In 1994, Congress passed the Public Safety and Recreational Firearms Use Protection Act, a federal assault weapons ban that prohibited the manufacturing of more than 100 firearms for civilian use, including the AR-15. That ban sunset in 2004, as Congress failed to secure sufficient votes to renew.

Since the early 2000s, there have been calls by prominent Democrats to renew a similar ban. Sen. Dianne Feinstein, who is credited as the politician behind the assault ban, introduced the Assault Weapons Ban of 2023 in late January. No progress has been made on the bill.

Some states, including Washington, California, and New Jersey, have restrictions on assault weapons that impact the possession of firearms like the AR-15. And in Texas, state lawmakers on Monday advanced a gun control bill that would increase the legal age to purchase an assault-style weapon to 21.

President Biden also showed his support for an assault weapons ban on multiple occasions, including a 2019 New York Times op-ed, and most recently after the shooting in Allen, Texas on May 6. “Once again I ask Congress to send me a bill banning assault weapons and high-capacity magazines,” he said in a statement. “I will sign it immediately.”