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National Issue

Highly Lethal Firearms and High-Capacity Magazines

Certain semi-automatic firearms, informally referred to as “assault weapons,” are military-style firearms with high muzzle velocity and a rapid rate of fire. High-capacity magazines are ammunition that allow firearms to be discharged repeatedly without reloading. Together, these kinds of firearms and magazines increase the lethality of gun violence. Sandy Hook Action Fund supports legislation prohibiting the sale and transfer of highly lethal firearms and magazines, especially to people under the age of 21.

What Does the Term, “Assault Weapons” Mean?

Although the definition of an assault rifle is “a military firearm…that has the capacity to switch between semi-automatic and fully automatic fire,” today, many policymakers and the media use “assault weapons” to describe semi-automatic firearms intended to fire multiple rounds in quick succession. These semi-automatic firearms can be used with detachable magazines that can fire more than 10 rounds of ammunition. These weapons were primarily designed for use in war and battlefields. But because there’s no federal restriction on their sales, civilians have been able to purchase these kinds of weapons to carry out some of our nation’s deadliest mass shootings.

What Are High-Capacity Magazines?

High-capacity magazines or “large-capacity magazines” are those that contain more than 10 rounds of ammunition. They can be used with any semi-automatic firearm that accepts a detachable magazine, including handguns, and allow the firearm user to fire repeatedly for longer periods of time without having to reload.

Why Limit Access?

Every time a shooter must pause to reload, there is an opportunity for lives to be saved. High-capacity magazines and semi-automatic weapons drastically reduce these opportunities, increasing the ability of a shooter to harm large numbers of people quickly. 

The shooter at Sandy Hook Elementary School had three weapons, including a military-style rifle, and 10 30-round magazines in his possession. In four minutes, he shot 154 bullets, killing 20 children and six adults. When he had to pause to reload, 11 children were able to escape.

How Effective Are Restrictions?

Laws restricting possession of these kinds of semi-automatic weapons and high-capacity magazines have been shown to be the best predictors of a state’s rate of mass shootings.1  States without these laws have significantly more high-fatality mass shootings and significantly higher death rates from such incidents than states with limits in place.2

From 1994 to 2004, federal law made it illegal to transfer or possess large capacity magazines and certain semi-automatic firearms in the U.S. During this time, mass shooting fatalities were 70% less likely to occur than in periods before or after the law’s enforcement.3 After the law expired in 2004, there was a 183% increase in in high-fatality mass shootings and a 239% increase in deaths resulting from such shootings.4

Which States Have Magazine Limits?

As of June 2020, nine states and the District of Columbia have laws in place restricting the sale and possession of high-capacity magazines: California, Colorado, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey, New York, and Vermont. Of those nine states, the following  also ban the sale of assault weapons: California, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey, and New York.

What Can I Do?

Call on Congress to pass proven gun safety policies:

The GOSAFE Act would increase federal regulation of certain semi-automatic firearms, large-capacity magazines and related conversion devices.

The Keep Americans Safe Act (S. 298 / H.R. 625) would prohibit the sale and transfer of high-capacity magazines.

Related Issues

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Temporary Transfer Orders, (i.e., Extreme Risk Protection Orders (ERPOs) or “red flag laws”) empower family members, law enforcement, and other key individuals to respond to warning signs of potential violence or suicide.

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  1. Sam Petulla, “Here is 1 correlation between state gun laws and mass shootings,” CNN, October 5, 2017.

  2. Louis Klarevas, Andrew Conner, David Hemenway (2019), “The Effect of Large-Capacity Magazine Bans on High-Fatality Mass Shootings, 1990-2017,” American Journal of Public Health 109, 1754-1761

  3. Charles DiMaggio et al., “Changes in US Mass Shooting Deaths Associated with he 1994-2004 Federal Assault Weapons Ban: Analysis of Open-source Data,” Journal of Trauma and Acute Care Surgery 86, no. 1 (2019): 11-19.

  4. Christopher Ingraham, “It’s time to bring back the assault weapons ban, gun violence experts say,” The Washington Post, February 15, 2018.

  5. Gun Policy Remains Divisive, But Several Proposals Still Draw Bipartisan Support,” Pew Research Center, October 18, 2018.