Bump stocks allow semi-automatic rifles to simulate automatic fire. The gunman who opened fire on tens of thousands of concertgoers in Las Vegas last October had attached bump stocks to at least a dozen assault-style rifles, law enforcement officials said. California and New York had banned the devices before the Las Vegas shooting. George Frey / Reuters A bump stock replaces the standard stock of a semi-automatic rifle to increase the firing rate. At least 15 states and a number of local jurisdictions have taken taken up proposals to ban bump stocks since the shooting.

Source: Huffington Post February 01, 2018 05:01 UTC