Here's how the polarizing M16 or AR-15 rifle went from a symbol of America's lost war in Vietnam to being owned by about 16 million Americans in 70 years
Reporter Betsy Halstead learns how to fire an M16 automatic rifle during the Vietnam War in 1965.
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The M16 or AR-15 rifle is one of the US's most divisive symbols
To gun enthusiasts, it is an effective, lightweight weapon. To anti-gun advocates, it's a symbol of mass shootings.
Experts estimate approximately 16 million adults in the US now own at least one of these rifles.
On Monday, a mass shooter killed three students and three adults at a school in Nashville. The shooter used two AR-15 rifles in the attack.
Semiautomatic rifles, including AR-15s, are becoming more common weapons used in recent mass shootings in the US, according to the National Criminal Justice Association. Since 2012, 10 out of 17 of the deadliest shootings in the country featured an AR-15 rifle, the Independent reported.
AR-15 rifles are light, accurate, and quick. When they were used by the military, they were called M16 rifles.
As of 2023, about 16 million adults in the US own at least one, according to polling conducted by The Washington Post and Ipsos. It is the country's best-selling rifle, but it has also become a divisive political symbol.
According to CJ Chivers, when a discussion turns to AR-15s, it stops being rational.
"The conversation is burdened by history, cluttered with conflicting anecdotes, and argued over by passionate camps," Chivers wrote in an article for The New York Times.
In the 1950s, Eugene Stoner, an engineer with firearms company ArmaLite, was tinkering with gun designs in his garage.
Soldiers looking at an M-15 rifle in 1965.
Stuart William MacGladrie/Fairfax Media/Getty Images
He wanted to create a new gun that could shoot steadily with a single pull of the trigger after studies showed soldiers dealing with the pressure of combat during World War II and the Korean War were not pulling the trigger on their weapons.
Stoner ended up inventing the AR-15 (as in the "ArmaLite Rifle) to rival the Soviet-created AK-47. He understood the importance of a light gun and how deadly a small bullet could be.
A pile of empty brass casings from M16 rifles on the group at the Fort Dix firing range, New Jersey, in 1967.
Leif Skoogfors/Getty Images
He spoke to Congress about his gun and explained its effectiveness, saying all bullets were designed to fly through the air, but they became unstable when they hit a target.
What wasn't so obvious was that a smaller bullet grew unstable quicker and caused far more damage to the target — meaning more brutal injuries for their opponents.
In a recent investigation, The Washington Post examined the damage a modern AR-15 can inflict, finding an AR-15 bullet can destroy entire organs or rip apart a human skull.
A US soldier holding an M16 rifle beside abandoned vehicles with their doors open in Saudi Arabia in 1991.
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Joseph Sakran, a trauma surgeon at Johns Hopkins Hospital and a gunshot survivor, told The Washington Post that when he operated on people who had been shot by an AR-15, their body tissue "literally just crumbled into your hands."
The Washington Post compared the bullet's damage to the wake of a boat — where a blast ripples out, damaging body parts otherwise untouched by the bullet.
Unlike the cumbersome M-14 that soldiers had been using, the AR-15 was accurate, quick, and light to carry. Soldiers could go into battle with it, as well as plenty of ammunition.
A soldier uses his M16 during a battle in the Vietnam War in 1971.
Neal Ulevich/AP
It used a gas operating system, making reloading quicker, and it included a new design that redirected gas from the fired cartridge, which made it easier to aim.
After initial testing in 1958, the US government bought 8,500 in 1962 and renamed it the M16. An internal report from the Pentagon called the gun "an outstanding weapon with phenomenal lethality."
But the design of the M16 wasn't ready for combat. The government probably should have refined the design. Instead, it hurried out production of the rifle.
US Marines in Vietnam use their M16 rifles in 1968.
AP
By 1966, issues with the M16 were widespread. Soldiers' rifles were jamming during battles. A report from 1967 said four out of every five troops from a group of 1,585 had dealt with jamming.
Paratroopers carry a wounded soldier while another holds an M16 in Vietnam in 1965.
Horst Faas/AP
It got so bad that soldiers had to use a metal rod to dislodge a cartridge case. The gun was compared to a single-shot musket rifle.
At the same time, American firearms manufacturer Colt Industries was working on modifying the M16. By 1967, it was made of plastic, aluminum alloy, and steel and was capable of shooting 30 rounds over nine football fields at a speed far faster than the speed of sound.
A cavalry soldier looks through a "starlight scope" that is attached to an M16 rifle in Vietnam in 1967.
During this period, Colt also turned to the domestic market. The company released a civilian M16 which was, once again, called an AR-15. It had the same gas operating system and was advertised to campers and hunters.
A weapons expert shows an officer how to use an AR-15 at a firing range in 2002.
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Though the M16 was fully automatic, the AR-15 was a semi-automatic weapon, meaning one-trigger pull shot one bullet, and the gun automatically reloaded the chamber.
The National Rifle Association called it "America's rifle." It later was advertised using questions like, "Should you shoot a rapist before he cuts your throat?"
A table of bumper stickers at an NRA convention in 1995.
After 1977, when the patent for Stoner's original gas system expired, a dozen manufacturers started selling their own AR-15 rifle, and "AR-15" became an umbrella name for a type of rifle.
People looking at guns at an NRA convention in 1995.
But the AR-15 didn't become a domestic hit overnight. A large portion of the gun industry wasn't sure about it. Many people called it the "black rifle" and considered it too expensive and ugly for hunting.
An army instructor inspects US-made M16 rifles during a training exercise in El Salvador in 1982.
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Instead, throughout the 1980s, AR-15s were mainly bought by law enforcement and "survivalists."
Things began to change in 1989 after a mass shooting at Cleveland Elementary School in Stockton, California. A lone gunman shot 34 people, killing 5 children, before killing himself. In response, Colt stopped selling AR-15s for a whole year.
Daniel Correa shows one of the guns that was used in the mass shooting at Cleveland Elementary School in Stockton, California.
AP
But Chris Bartocci, former Colt employee and author, told CNN the shooting actually increased the AR-15's profile. Before the shooting, many people didn't know this type of gun was available on the domestic market. But they knew about it afterward.
Weapon bans were discussed during the Bush administration, but nothing was formalized until 1994 when the Clinton administration passed a bipartisan law that banned the manufacturing and selling of about 118 types of military-grade guns.
President Bill Clinton shakes hands with Stephen Sposato, whose wife was killed by a gun violence, after he signed a sweeping crime bill that included a ban on assault weapons.
J. Scott Applewhite/AP
They were defined for the first time as "assault weapons." The ban was imposed on guns that had magazines that could hold more than 10 bullets.
"Today, at last, the waiting ends," then-President Bill Clinton said at the signing. "Today, the bickering stops, the era of excuses is over."
But the new law didn't include guns that were made before 1994, and due to loopholes, buyers could still buy slightly modified AR-15s. The Washington Post called the law "largely toothless."
A civilian tries out an M16 at a gun shop in 1993.
Pat Greenhouse/The Boston Globe/Getty Images
Some experts also believed that banning assault weapons made them more attractive to some Americans.
In the early 2000s, the gun industry, which had been in a slump, harnessed the aftermath of the 9/11 attacks to stoke patriotism and increase demand for AR-15s.
"There has never been a better accidental advertising campaign in history," Doug Painter, former president of the National Shooting Sports Foundation, told The Washington Post.
This continued into 2004 when the Clinton administration ban ended. At this point, the US was in the midst of wars in Afghanistan and Iraq, and patriotic images of soldiers using M16s prompted an increase in civilians buying AR-15s.
A woman is instructed how to handle an M16 rifle by Marine Sergeant Richard Diaz in California in 2002.
First-person shooter video games like Call Of Duty increased the popularity of AR-15s by showing people what it was like to use one in a virtual setting.
AR-15s could also be reconfigured based on their owners' needs — cosmetically or for different uses, like hunting, target practice, or law enforcement — which helped their growing popularity.
A gun salesman holds an AR-15 with a bayonet mount at a Pittsburgh gun shop in 2004.
In 2005, the gun lobby was bolstered by the Bush administration. It passed a law called the Protection of Lawful Commerce Arms Act, which protected gun companies from being sued when their guns were used unlawfully, like in a mass shooting.
Former President George W. Bush is applauded for signing the Protection of Lawful Commerce Arms Act in 2005.
In 2007 and 2008, during Barack Obama's run for president, the gun lobby didn't miss a beat. They claimed the US had never "faced a presidential candidate — and hundreds of candidates running for other offices — with such a deep-rooted hatred of firearm freedoms."
A sign explaining a version of Obama's gun control policies sits taped at a gun store in 2008.
Kasha Broussalian/Digital First Media/Boulder Daily Camera/Getty Images
The fear of another gun ban caused sales to go up again. According to CNN, gun production increased by more than 50% once Obama took office.
According to Ryan Busse, a senior policy advisor who worked for a gun control policy group called Giffords, it was during this era that the AR-15's image began to change.
A woman holds an AR-15 at a gun rights rally at the Utah State Capitol in 2013.
George Frey/Getty Images
"By the time Obama was leading in the polls in 2007, the AR-15 was starting to become the poster child, both of industry growth, but also what we now see, which is right-wing politics wrapped in and around the firearms industry and firearms ownership," Busse told Poynter.
The AR-15's popularity began to show in another way, too — it became more prevalent in mass shootings. From 1996 to 2009, AR-15s were used in one out of every three mass shootings. But from 2009 to 2019, it was used in more than half of mass shootings.
People at a memorial for a mass shooting in Oregon in 2019, where the shooter used an AR-15 rifle.
Scott Olsen/Getty Images
At the same time, a Pew gun survey conducted in 1999 and 2017 showed gun owners had done a complete reversal in why they bought guns. In 1999, 26% of participants owned a gun for protection. By 2017, it was up to 67%.
Despite the increase in use during mass shootings, the industry continues to grow. As of 2023, about 16 million adults in the US own at least one AR-15 rifle. It has become the country's best-selling rifle.
A man and his 7-year-old son look at an AR-15 rifle at an NRA convention in 2022.
Brandon Bell/Getty Images
The gun industry believes there are about 20 million AR-15s across the country.
In 2021, President Joe Biden said if he could do one thing to the gun industry, it would be to let victims of gun violence sue gun makers. But so far, he hasn't achieved that.
President Joe Biden speaks about efforts to reduce gun violence at The Boys & Girls Club of West San Gabriel Valley in Monterey Park, California.
Evan Vucci/AP
Last year, his administration did pass a new gun law, but it doesn't specifically restrict AR-15s and is actually less restrictive than the 1994 law.
Going forward, it remains difficult to impose any limits on selling and purchasing AR-15s because of the rifle's popularity and powerful lobbying by gun companies and the NRA.
A man holds an AR-15 while the gun shop owner looks on at a Maryland gun shop in 2023.
