Justice Department officials are forging ahead with plans to ban rapid-fire bump stocks, Attorney General Jeff Sessions said Tuesday — a move that would likely set the stage for long legal battles with gun manufacturers while the devices remain on the market. Sessions said top officials within the department believe gun accessories like the ones used in last year’s Las Vegas massacre can be banned through the regulatory process. The federal Bureau of Alcohol, Tobacco, Firearms and Explosives previously said it was powerless to restrict the devices without action from Congress. The devices allow semi-automatic rifles to resemble a fully automatic weapon. The ATF approved them in 2010, finding they don’t amount to machine guns, which are prohibited under federal firearms law. “We’ve had to deal with previous ATF legal opinions, but our top people in the Department of Justice have believed for some time that we can, …