New Supreme Court Brief Challenges Key Arguments Behind Assault Weapon and Magazine Bans

A new amicus brief filed with the U.S. Supreme Court is challenging some of the central arguments used to defend so-called assault weapon and magazine bans. Filed by the Firearms Policy Coalition Action Foundation and criminologist Professor Gary Kleck, the brief supports the challengers in Viramontes v. Cook County and Grant v. Rovella.

One of the brief’s primary arguments is that courts and lawmakers frequently blur the distinction between semi-automatic rifles and the magazines used in them. An AR-15, for example, can accept magazines of different capacities without changing the underlying firearm. The brief argues that magazine capacity is therefore a characteristic of the detachable magazine—not the rifle itself—and that governments should not rely on concerns about magazine capacity to justify bans on commonly owned rifles.

The filing also challenges the public-safety arguments surrounding magazine restrictions. According to research cited in the brief, studies have not established a clear connection between larger-capacity magazines and increased lethality in criminal shootings. The brief also cites research finding that criminal shootings typically involve only a small number of rounds, raising questions about whether limiting magazines to 10 rounds would materially affect most firearm-related crimes.

Another major argument concerns the frequently cited “pause to reload.” Supporters of magazine restrictions argue that forcing an attacker to reload more frequently can provide victims or law enforcement an opportunity to intervene. The brief disputes how often that occurs in practice, citing research in which only one incident potentially involved an intervention during a reload and noting that attackers in many incidents possessed multiple firearms or magazines.

The brief also argues that magazine restrictions affect lawful self-defense. Research cited in the filing found that nearly 29% of defensive gun users surveyed faced multiple attackers, and the brief points to documented incidents in which defenders fired more than 10 rounds. Its argument is that predetermined magazine limits cannot account for the circumstances an individual may encounter during an actual defensive situation.

Ultimately, FPC Action Foundation and Professor Kleck are asking the Supreme Court to treat challenges to rifle bans and magazine restrictions as related but legally distinct constitutional questions. They argue that governments defending bans on AR-15-style rifles should have to justify restrictions on the firearms themselves rather than relying primarily on arguments concerning detachable magazine capacity.

The brief asks the Supreme Court to reverse the lower court decision, with the outcome of these cases potentially carrying significant implications for assault weapon and magazine restrictions across the country.