Blueprints for 3D printable guns will be made available on the internet this week after a judge rejected a last-minute challenge by gun control groups.
US District Judge Robert Pitman in Austin, Texas denied the request the Brady Center to Prevent Gun Violence, Everytown for Gun Safety and the Giffords Law Center to Prevent Gun Violence at a hearing.
He said he was sympathetic to the gun control groups' concerns but questioned their legal standing to intervene in the case.
The court decision means that the company Defense Distributed will be allowed to legally publish the designs for several gun models as early as this Wednesday, August 1.
The groups had attempted to intervene after the Trump administration came to a settlement with the company to legally publish gun blueprints online.
The US government had ordered the blueprints taken down in 2013, arguing they were a national security risk.
It prompted Defense Distributed founder Cody Wilson to sue two years later, claiming his free speech rights had been violated.
The gun control groups had argued not halting the distribution would "cause immediate and irreparable harm to the United States national security" and that of individual U.S. citizens.
The 3D files include blueprints for a plastic AR-15 semiautomatic assault rifle, a weapon that has been used in many US mass shootings, as well as other firearms.
But Lawrence Keane from the National Shooting Sports Foundation, a trade association for gun manufacturers, said the concerns were overblown.
He told Reuters: "I don't see it likely at all that criminals will use this clunky and expensive technology."