By Carolyn Crist

(Reuters Health) – A ban on gun magazines that hold a large number of bullets could lower the number of deaths during mass shootings in the U.S., a new study suggests.

Attacks with large-capacity magazines had more than a 60% higher average death toll, researchers write in the American Journal of Public Health.

“One of the strategies for surviving an active shooting is to ‘run, hide, fight.’ For those in the line of fire, the opportunity to flee, take cover, or counterattack is expanded if an interruption in the shooting occurs,” said Louis Klarevas of Columbia University’s Teachers College in New York City, who led the study.

Large-capacity magazines are defined as ammunition-feeding devices that hold more than 10 bullets. In 1994, Congress enacted a federal assault weapons ban, which limited these types of magazines, but the ban expired a decade later. Today, nine states and the District of Columbia restrict possession of these large-capacity magazines, but the bans vary in terms of maximum bullets allowed and applicable firearms.

“Every time gunmen are forced to pause their attacks in order to reload magazines – something that will occur with greater frequency if magazines have a maximum capacity of 10 bullets as opposed to 30, 50, or 100 bullets – it creates such an opportunity, which provides those in harm’s way with the precious seconds they need to take life-saving actions,” Klarevas told Reuters Health by email.

Klarevas and colleagues analyzed state data from 1990-2017 on high-fatality mass shootings, i.e., resulting in 6 or more deaths.

During the study period, there were 69 high-fatality mass shootings, including 44, or 64%, involving large-capacity magazines. The average number of deaths was 12 in shootings involving large-capacity magazines, compared to an average of 7 deaths per shooting without large-capacity magazines.

High-fatality mass shootings were twice as likely to happen in states where high-capacity magazines weren’t banned. And overall, these shootings became more frequent after September 2004, when the federal assault weapons ban expired, the authors note.

After accounting for variables such as population density, income, education, unemployment, per-capita prison population and percentage of households with a firearm, mass-shooting rates were still more common and fatality rates were still higher in states without bans on high-capacity magazines.

Various groups have called for more detailed background checks, assault weapons bans, child access prevention laws, safe storage laws and extreme risk protection, but more research is needed to better understand how laws would help, the study authors say.

“We still have little data to support any of the policies that are being offered, regardless of where you fall on gun control. Having the data to analyze these proposals is important,” said Jaclyn Schildkraut of the State University of New York at Oswego. Schildkraut, who wasn’t involved with this study, researches mass shootings, school shootings and school lockdown drills.

She pointed out, for instance, that even in states where large-capacity magazines are banned, about 55% of shooters used them. That percentage is still a significant amount with a ban, she said.

“This speaks to the fact that, at the end of the day, criminals don’t follow the law,” she told Reuters Health by phone. “We all have the same goal of reducing the loss of life during shootings, and this looks at one slice of the homicide problem in the U.S.”

SOURCE: American Journal of Public Health, online November 6, 2019.