Article snippet: Bump stocks were virtually unheard of on Capitol Hill until this week. Even some anti-gun lobbyists told ABC New this week that the gun attachments weren’t on their radar before the massacre in Las Vegas Sunday. But that that is all changing, and fast. A weapons expert described the so-called bump stock as a legal attachment that simulates automatic fire on semiautomatic weapons. In essence, it uses the momentum of the gun's recoil to rapidly bump the trigger, allowing the gun to fire much faster, albeit with less accuracy. The expert, who requested anonymity, said a shooter could fire 550 to 650 rounds a minute with a bump stock attachment on an AR-15 or AK-47. The Las Vegas shooter used the device. Sen. ban assault weapons in 2013 that failed in the Senate, 40-60. Democrats will need significant Republican support for anything to pass. More than a dozen influential Republican lawmakers have told ABC News they are either supportive of a ban, or at least favor reviewing the issue. “The fact that fully-automatic weapons are already illegal and this makes another weapon capable [of automatic fire]; I would be supportive of that,” Senate Homeland Security Chairman Ron Johnson, R-Wis., said when asked Wednesday about legislation to ban bump stocks. Senate Minority Whip John Cornyn, a Texas Republican, told reporters Wednesday there should be a hearing. "I talked to Chairman [Chuck] Grassley of the Senate Judiciary Committee, and I believe ... Link to the full article to read more