From Guns.com:

As gun rights groups and Second Amendment advocates sought a nationwide injunction against the move with the U.S. Supreme Court on Monday, the pending rule change by government regulators to reclassify bump stocks as “machine guns” was set to become effective on March 26. In response, RW Arms, the leading retailer of the devices, announced they would seek to turn in their remaining inventory of bump stocks to the Bureau of Alcohol, Tobacco, Firearms and Explosives.