Man jailed for offering to sell 3D printed guns on Facebook

A judge who jailed a man for trying to sell a 3D-printed machine gun says she is concerned that the person who made the gun is still at large.

Benjamin Michael William Mumford, 39, pleaded guilty in the Brisbane District Court on Thursday to five counts of supplying a shortened firearm as well as unlawfully possessing three homemade shotguns and 13 rounds of ammunition.

Mumford also pleaded guilty to possession of handcuffs, a telescopic baton and a small amount of methamphetamine.

Crown prosecutor Ron Swanwick said police searched Mumford’s home in the northern Brisbane suburb of Alderley on March 7, 2023.

Police examined Mumford’s phone and discovered he had attempted to sell a 3D-printed replica machine gun to five different people over 10 days using private messages on Facebook.

Mr Swanwick said the firearm was less than 75 centimeters long and was designed to fire .223 caliber bullets, but was temporarily inoperable.

“On March 5 he offered to sell the replica for $10,000 and he sent a photo of himself holding it,” Mr Swanwick said.

The 3D printing process involves using a digital design file and computer-controlled equipment to create a physical object typically using hundreds of layers of molten plastic.

Judge Vicki Loury said she was concerned Mumford had refused to co-operate with police.

“What he didn’t do was tell the police where these guns came from. Someone obviously has a brief for printing a replica machine gun. Who is this person?” she says.

Defense lawyer Francis Martin said none of the sales took place and that Mumford was trying to find money to buy drugs.

“I hope he has a future. He is planning to take a baking course and buy a house,” Mr Martin said.

Judge Loury said Mumford’s previous record of possessing a loaded pistol showed he had not been deterred from obtaining weapons.

Mumford was sentenced to four years’ imprisonment with a mandatory minimum term of two and a half years’ detention for supplying shortened firearms.

Mumford will be eligible for parole in September 2025 because he has already served 429 days in custody.