Tens of millions of Americans own an AR-15.

That’s according to a new Washington Post-Ipsos poll released on Monday. The poll surveyed Americans more broadly to gauge gun ownership and found that 31 percent of adults report owning guns. Of those, the poll found that 20 percent own an AR-15 rifle. 

“Taken together, the polls find that 6 percent of Americans own an AR-15, about 1 in 20,” Post reporter Emily Guskin wrote. “The data suggests that with a U.S. population of 260.8 million adults, about 16 million Americans own an AR-15.”

The survey is the latest evidence to confirm the popularity of AR-15s and similar rifles, often dubbed “assault weapons” by critics, among the American gun-owning public. The extent of their ownership could factor heavily in the political debate over their continued legality as multiple blue states mull bans and gun rights groups prepare to contest them.

That finding provides new insight into ownership of the popular rifle, which is valued by gun-rights advocates for its versatility and modularity but reviled by gun-control activists for its use by shooters in a number of high-profile attacks.

The poll’s estimates land in the ballpark of previous estimates. The National Shooting Sports Foundation has previously estimated that there are over 24.4 million AR-15s and similar rifles—which it calls “modern sporting rifles”—in civilian hands as of 2022. The National Firearms Survey, conducted in 2021 by Georgetown professor William English, found that 30.2% of gun owners, about 24.6 million people, indicated owning an AR-15 or similarly styled rifle.

In its landmark Heller decision, the Supreme Court found that the Second Amendment protects arms “in common use” by “law-abiding citizens for lawful purposes.” Whether ownership among tens of millions of Americans is enough to fall into that camp may help determine the constitutionality of AR-15 bans. Although, a federal judge in Delaware ruled on Monday that state’s ban can stand despite the popularity of the rifle.

Self-defense was the most popular reason AR-15 owners in the poll gave for buying the gun. Around one-third listed it as the main reason for ownership, but nearly two-thirds said that it was “a major reason” for purchasing the rifle. Other popular answers given in roughly equal numbers included recreation, target shooting, hunting, and exercising their Second Amendment rights.

The poll found that AR-15 owners were around 20 percent more likely to be male than other gun owners and 30 percent more likely to be male than the U.S. adult population. Only 19 percent of AR-15 owners self-identified as female. AR-15 owners were also more likely than the adult population as a whole, and about equally likely as other gun owners, to be white. Three-quarters of AR-15 owners said they were white, while 11 percent said they were Hispanic, and nine percent said they were black.

AR-15 owners were also more likely to live in a suburban area, have a higher income, identify as politically Independent, and fall between the ages of 40-64 than other gun owners and the population as a whole. They were also significantly more likely to have served in the military, though nearly three-quarters of AR-15 owners said they had not served.

The poll identified a regional divide in AR-15 ownership as well. Nearly half of all AR-15 owners reported living in the South, while roughly one-quarter and one-fifth reported living in the West and Midwest, respectively. Only ten percent of AR-15 owners said they lived in the Northeast.

This Washington Post-Ipsos poll was conducted from September 30-October 11, 2022, among a random national sample of 2,104 gun owners, including 399 AR-15-style rifle owners. The margin of error for the sample of AR-15-style rifle owners is 5.5 points.