Jeffrey Miron
Bump stocks are devices that enable semi�​automatic weapons to fire faster—although still slower than—fully automatic weapons. Bump stocks became the target of legal and public scrutiny after a gunman used them in the 2017 Las Vegas mass shooting, after which then�​President Donald Trump called for a ban. The Bureau of Alcohol, Tobacco, and Firearms (ATF) responded by reclassifying bump stocks as machine guns, effectively banning them.
The Supreme Court recently reversed the ban, arguing that it lacks specificity and puts any accessory that makes firearms easier or safer to shoot at risk of an ATF ban. Supporters of the now�​defunct ban are therefore arguing for Congress to explicitly ban bump stocks.
A new ban, however, is unlikely to reduce the harm from mass shootings. Bump stocks can easily be made at home, via 3D printing or improvised devices produced from standard household items.
Bump stocks make semi�​automatic weapons significantly less accurate than automatic weapons because of the recoil movement of the gun. The bump stocks used in the Vegas shooting may actually have reduced the number of fatalities.
Lemoni Matsumoto, an undergraduate at the University of Chicago, contributed to this article.
