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

In the 1950s, Eugene Stoner, an engineer with firearms company ArmaLite, was tinkering with gun designs in his garage.

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.

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.

The US army wanted this kind of lethal weapon for the Vietnam War. It needed a decent alternative to the North Vietnamese's AK-47s.

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.

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.

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.

Even so, the US army kept to its story — this was the weapon that would win them the Vietnam War.

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.

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.

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?"

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.

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.

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.

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.

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."

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.

Source: 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.

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.

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.

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."

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.

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.

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.

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.

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.

As Senator Chris Murphy told The Washington Post, protecting the AR-15 has become the gun lobby's "number one priority."