Before Payton Gendron stormed into a Buffalo, New York, supermarket and killed 10 people in a racially motivated rampage in 2022, he stocked up on ammunition made for the Army.
"Since I will be expecting to shoot through the front door windows at the security guard, I will have to use the best barrier penetration ammo I can get," he said in his manifesto. On his shopping list was 5.56mm ammunition made in the Lake City Army Ammunition Plant in Missouri.
A New York Times investigation found that ammunition from that plant has been used in at least 12 high-profile mass shootings, including at Robb Elementary School in Uvalde, Texas; Marjory Stoneman Douglas High School in Parkland, Florida; and the Century 16 movie theater in Aurora, Colorado. Ammunition from Lake City has also been seized by law enforcement from gangs, Mexican cartels, and anti-government militias.
Read Next: Top Republicans Fume After Botched Army Terrorism Briefing Named Anti-Abortion Groups
A group of Democratic lawmakers wants to know how the Lake City plant, a government-owned facility operated by Olin Winchester under a Pentagon contract, produced ammo used in some of the country's most violent crimes.
"[The Department of Defense] must ensure that public tax dollars no longer subsidize the production of military-grade ammunition that finds its way onto our streets and fuels mass shootings," the group of lawmakers wrote Sunday to Defense Secretary Lloyd Austin and Army Secretary Christine Wormuth.
In the letter penned by Sens. Elizabeth Warren, D-Mass.; Alex Padilla, D-Calif.; and Mazie Hirono, D-Hawaii; and Reps. Jamie Raskin, D-Md., and Robert Garcia, D-Calif., they ask the Pentagon to explain oversight of the plant, as well as what details it has on the commercial end of its business.
Meanwhile, a coalition of 20 attorneys general called on the White House in January to investigate Lake City ammunition being sold on the civilian market -- much of which is done online.
In an executive order in March, President Joe Biden directed the Pentagon to develop a public safety plan in relation to weapons acquisition, though the specifics on what that could mean in practice are scant.
The Pentagon declined to comment on its progress complying with the executive order, how much ammunition has ended up on the civilian marketplace, or what mechanisms are in place for oversight on the plant.
Lake City, which the military has invested some $860 million in to beef up its production lines since the wars in Afghanistan and Iraq, is contractually required to produce some 1.6 billion rounds of ammunition per year for the Army, though the service hasn't come anywhere close to buying that much ammo in a given year, according to the lawmakers' letter.
The Army has a deal with Winchester that whatever ammo isn't purchased by the service can be sold commercially on the civilian market. The idea behind the excess capacity is that the service can quickly ramp up its ammunition stockpiles in the event of war but won't need to drain Lake City's inventory during typical years.
Those rounds are branded with the hallmark "LC" for Lake City on the bottom of the bullet. The ammo has a following among gun enthusiasts. The rounds are generally seen as high quality, and their sturdiness makes the brass easier for die-hard enthusiasts to recycle into new rounds. The ammo is also routinely marketed in stores and by the manufacturer itself as the type used by the military.
"Winchester is the largest manufacturer of small-caliber ammunition for the U.S. military," the manufacturer notes on its website. "Proven in battle for more than 100 years, we've delivered trusted ammunition products for civilians, law enforcement and military."
In March, the Army awarded Olin Winchester the contract to produce ammunition for the service's replacements for the M4 rifle and Squad Automatic Weapon, or SAW, machine gun. The ammo for the new weapons will be larger 6.8mm rounds, far more capable of piercing the kind of armor used by military and law enforcement.
Related: The Army Has Finally Fielded Its Next Generation Squad Weapons
