An AR-15 ammunition factory built to supply the military shifted to commercial sales and is now tied to more than a dozen mass shootings

• A World War II-era AR-15 ammo factory is linked to several mass shootings, the Times found.
• The Lake City Army Ammunition Plant was built to supply the US military. 
• But the plant shifted to commercial sales in the last decade.

A World War II-era ammunition factory meant to supply the US military has been linked to more than a dozen mass shootings.

The Lake City Army Ammunition Plant shifted to commercial sales in 2011 and is now one of the biggest manufacturers of commercial AR-15 ammunition in the United States. According to The New York Times, it has made "hundreds of millions" of commercial rounds every year since 2011.

The facility was built during World War II and has since been operated by US government contractors to produce ammunition, but its focus has gradually shifted to commercial production as military demand waned, The Times reported.

By 2021, commercial production in the facility was more than two times higher than the rate of production for military ammunition, The Times found.

While The Times found that the "vast majority" of rounds sold from Lake City to retailers end up in the hands of law-abiding citizens, they have also shown up in a number of mass shootings.

Rounds from Lake City have been tied to at least a dozen mass shootings, including the 2012 Aurora, Colorado movie theater shooting, the 2018 Marjory Stoneman Douglas High School shooting in Parkland, Florida, and the 2017 Las Vegas Strip mass shooting, the deadliest in US history, the report says.

According to the report, the gunman responsible for the Buffalo supermarket shooting that killed 10 people in May 2022 also mentioned Lake City in his manifesto. The shooter reportedly wrote that he planned to fire at security guards through a window and said the rounds made at Lake City were "the best barrier penetration ammo I can get."

Semiautomatic rifles such as the AR-15 are becoming the most commonly used weapon in mass shootings in the United States, according to the National Criminal Justice Association. As of May 2022, the United States had 20 million AR-style rifles in circulation. There are nearly 400 million guns owned by US civilians in total.