WASHINGTON (Reuters) - Congress should consider legislation that would regulate “bump stocks,” the attachments that allowed the Las Vegas gunman to fire his semi-automatic rifles more rapidly, U.S. Senator John Cornyn said on Wednesday. Cornyn, the second-ranking Senate Republican, told reporters that if the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) does not have the authority to regulate bump stocks,  “maybe that’s something we ought to consider giving them.” Cornyn, a member of the Senate Judiciary Committee, said he was urging panel Chairman Charles Grassley to call a hearing on bump stocks. “I’d like to hear from the ATF who previously during the Obama administration said they didn’t feel like they had the authority to regulate those. I’m not sure I agree with that,” the Texas senator said. On Oct. 1, a gunman in Las Vegas opened fire at an outdoor music festival killing 58 people and injuring nearly 500 others before killing himself, the deadliest mass shooting in modern U.S. history.  The attachments are legal and allow semiautomatic rifles to operate as if they were fully automatic machine guns, which are heavily restricted in the United States. Slide Fire Solutions, the maker of bump stocks, has announced that it is restarting sales of the product after a pause following the Las Vegas shooting. 