AR-15s are becoming even more popular.

More than 4.5 million ARs. AKs, and similar rifles were bought by American civilians since the last time their circulation was estimated, according to a new report. The National Shooting Sports Foundation (NSSF), the gun industry’s trade group, found there are now at least 24,446,000 of the guns in civilian hands. It said 2.7 million were produced or imported in 2020 alone–the most for any year on record.

“This is a truly significant figure that demonstrates – again – the popularity of this commonly-owned style of rifle,” Joe Bartozzi, NSSF President, said in a statement. “The firearm industry responds to market demand and this shows that during the elevated period of firearm sales that began in 2020, this particular style of rifle is the top choice for law-abiding citizens for hunting, recreational shooting and self-defense.”

The report shows the increasing popularity of AR-15s and similar rifles, which could impact how litigation over bans on those firearms, often labeled “assault weapons,” in some states play out. Whether a gun is in “common use” for lawful purposes was a key test for whether it is protected by the Second Amendment in the Supreme Court’s landmark Heller decision. Gun-rights advocates have used the number of ARs in circulation to argue bans on them are unconstitutional. They have enjoyed little success in federal court to this point, but last month’s Supreme Court decision in New York State Rifle and Pistol Association v. Bruen has reinvigorated advocates and resulted in a lower court decision upholding Maryland’s ban being vacated and remanded for further consideration.

The growing ownership of ARs may also help explain why the popularity of assault weapons bans has wained in recent years despite the guns being used in some high-profile shootings. Even as House Democrats pursue passing the first ban in decades this week, polling indicates support for the policy has decreased significantly. The latest polling from Gallup and Quinnipiac University found support for a ban fell even in the wake of the Uvalde shooting, with Quinnipiac showing support at an all-time low.

NSSF calculated the number of ARs and AKs in circulation by combining data from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) Annual Firearms Manufacturing and Exportation Report, U.S. International Trade Commission data, and internal estimates from the industry itself. It estimated the number of domestically-produced rifles and imports from 1990 through 2020. The estimates include semiautomatic AR-15s, AK-47s, and their derivatives, or what the industry calls “modern sporting rifles” (MSR).

The definition of MSRs does not precisely match the definition of assault weapons, though the two overlap significantly. Since the MSR definition focuses exclusively on AR-15s and AK-47s while varying assault weapons definitions focus on banning a combination of features, including pistol grips or flash suppressors, the overlap is not total. While assault weapons bans target AR-15s and AK-47s, many derivatives remain legal, as shown in the number produced between 1994 and 2004 when the federal assault weapons ban was in effect.

NSSF claimed ARs and AKs are popular because of their “accuracy, reliability, modularity, and low recoil. The group said they are the most popular rifles in the country.

“The MSR remains the most-popular selling centerfire semiautomatic rifle in the United States today,” NSSF said. “There are more MSRs in circulation today than there are Ford F-Series trucks on the road.”