Ever since the Supreme Court held, in 2008, that weapons in “common use” can’t be banned, lower courts have argued over what the term means. The National Shooting Sports Foundation, the gun industry’s trade group, has dragged questionable evidence into the now urgent debate. 

In June, NSSF research director Salam Fatohi testified in an Oregon lawsuit that sought to strike down a voter-approved ban on magazines capable of holding eleven or more rounds. His organization had submitted into evidence a chart suggesting that U.S. consumers had owned nearly 160 million such high-capacity magazines (HCMs) between 1990 and 2018. Gun interests have cited or introduced the chart in at least ten federal court cases since 2017, and the NSSF has referenced it in at least two friend-of-the court briefs, including one filed at the Supreme Court.

Fatohi explained that the figure had been extrapolated from federal firearm production and import data, as well as “industry estimates.” When questioned, however, Fatohi agreed that HCM possession — what the chart purported to show — and firearm production are distinct. Asked how the industry estimate was arrived at, Fatohi said he was unsure. He could not say how many NSSF member companies had been consulted. “So it could be two? It could be 20? It could be 200?” Satohi was asked. “Yes,” he responded.

When U.S. District Court Judge Karin Immergut, a Republican Trump appointee, upheld Oregon’s ban in July, she ruled that “the NSSF Magazine Chart is entitled to little weight.”

Mark Oliva, the NSSF’s director of public affairs, declined to answer questions for this story, citing The Trace’s connections to Everytown for Gun Safety. The group advocates for stricter firearms controls and provides financial support to The Trace. You can read more about our donors and position on editorial independence here

In August, Fatohi’s predecessor as NSSF research director, James Curcuruto, was deposed in a suit challenging California’s ban on HCMs. Curcuruto said that the industry estimates captured in the chart, which he believed was first produced around 2015, came from his discussions with then-NSSF president Steve Sanetti, former head of the gun company Sturm, Ruger, & Co. “So, to be clear, you essentially told Mr. Sanetti, ‘There [are] X number of pistols out there. How many do you think come with a magazine holding more than 10 rounds?’” Curcuruto was asked. “Yeah,” he replied. Curcuruto said no attempt was made to account for guns sold to law enforcement or siphoned to the black market. 

Under professional conduct rules, attorneys cannot offer evidence, such as the NSSF chart, that they know is false, but they are not required to make an exhaustive inquiry into its validity. Peter Joy, a professor at Washington University in St. Louis School of Law who specializes in legal ethics, said lawyers typically offer the best evidence they can muster and hope the court is receptive. “There is a certain degree of testing the waters sometimes with evidence,” he said.

In his deposition, Curcuruto stressed that the chart offered a good-faith estimate and that he was unaware of a reliable public source for magazine circulation figures. The lack of such a source may in part be due to the gun lobby’s longstanding opposition to government collection of firearms ownership data.  

Since the Supreme Court upended the standard for determining the constitutionality of gun laws in 2022, defining common use has become hugely important, particularly in cases involving so-called hardware bans, such as prohibitions on AR-15 style rifles and HCMs. Those who oppose such bans argue that common ownership equals common use. Supporters argue that the right measure is the frequency with which a weapon is actually used for self-defense, as the Supreme Court’s Second Amendment jurisprudence is centered on the right of self-defense.

Both sides in the Oregon case agreed that Americans own many millions of HCMs. Given the sheer number of guns produced that are designed to accept them, it follows that large numbers of high-capacity magazines are in circulation. The term high-capacity magazine has no universally accepted definition, but typically is applied to those that hold ten rounds or more (though many models hold 30, 40, 50 or even more rounds). Fourteen states have outlawed HCMs. In at least five of those states, the bans are being challenged. Ten states prohibit AR-15-style rifles, and in at least six, gun rights interests are seeking to strike down the bans.

Judges hearing these challenges have reasoned differently on the “common use” issue. Immergut, placing herself firmly on the frequency side of the debate, cited evidence suggesting that few rounds are fired in the overwhelming majority of defensive gun use cases. She ruled that “features unique” to HCMs — chiefly the ability to fire more than ten rounds without reloading — are rarely employed in self-defense situations, hence they can be banned.

On September 22, U.S. District Court Judge Roger Benitez overturned — for a second time — California’s HCM ban, which voters approved in 2016. Benitez, a gun rights darling who has been criticized for callousness and a lack of restraint, decided that the criterion for common use was simple prevalence. The NSSF chart featured as evidence in the case. “A person may happily live a lifetime without needing to fire their gun in self-defense,” Benitez wrote. “But that is not to say that such a person does not use their gun for self-defense when he or she keeps it under the bed with a hope and a prayer that it never has to be fired.”

With the state of Second Amendment law in flux, the Supreme Court will hear arguments in November in a case that will determine whether the federal government can prohibit people subject to domestic violence restraining orders from possessing guns. More broadly, a ruling in the case is expected to clarify the limits of so-called prohibited persons laws, which ban certain categories of people — such as felons — from having guns. Several magazine restriction and AR-15-style rifle ban cases are at the federal circuit court level, and the Supreme Court may be asked to define common use, with major implications for public safety. As The Trace has reported, HCMs are often used by mass shooters and associated with increased carnage. 

When California deposed Curcuruto in August, he never mentioned public safety, nor the Second Amendment. He could not recall either being raised in discussions of the group’s opposition to HCM bans. Protecting the financial interest of members was the driving force. “To the best of your recollection, were you ever provided with any other rationales as to why NSSF opposed the restrictions on large capacity magazines?” Curcuruto was asked. “No,” he replied. “That was the premise of it, you know, helping our members stay in business.”