Experts have warned that 3D printed guns are liable to fall apart or explode when firing, posing a potential threat to their users.

3D printed gun tes fire
Cody Wilson test fired the first 3D printed gun in Austin, Texas. (Credit: BBC)

On a company blog, London-based 3D printing firm Digits2Widgets said that, despite the successful test-firing of a printed gun developed by US student Cody Wilson, who now plans to post the blueprints for his gun online, home 3D printing would create a weapon of "poor engineering quality" which could potentially harm or kill the user:

"Cody Wilson's gun was printed on an industrial grade 3D printer. Industrial grade 3D printers are currently at a price well beyond domestic access level. Therefore and as Cody states, access to parts made on this grade of machine will be via Service Bureaus.

"Unlike potential homemade printed guns, Wilson's gun parts were built in a specific machine (bought on Ebay), running a specific material. There is currently a proliferation of 'home 3D Printers' coming on to the market. The level of precision detail that they can achieve and the poor engineering quality of their own plastic materials would make it suicidal to attempt to print and fire the gun made from any of these machines," Digits2Widgets continued.

Digits2Widgets also said that it had been approached by two newspapers, The Daily Telegraph and the Mail on Sunday, to create a 3D printed gun, but had declined.

Intense heat

3D printed guns, which are built using nylon and plastic, may fracture or explode when being fired due to the intense heat created inside the barrel. The pressure in a gun barrel on firing typically reaches 1000 atmospheres, while the temperature exceeds 200C. Powder residue left in the barrel from printing or friction left by a previously fired round could cause the gun to backfire and explode.

"It all depends on how hard the plastic is," Philip Boyce, a firearms expert at Forensic Scientific told The Guardian. "You might get one of these to fire 10 to 20 shots before it gives up the ghost. It would just disrupt - the barrel would fall apart, the chamber would fall apart."

"We fear that the next story will be about a child blowing their hand off while experimenting with a 3D printed gun," Jonathan Rowley, design director at Digits2Widgets told the BBC World Service. "This type of accident is the immediate danger of the project and will happen long before anyone is deliberately killed by one of these tools."

Rowley also called Defense Distributed, Wilson's project to share plans for a printable gun online, "irresponsible":

"If you look at these files, there are all sorts of attached text documents about how to put them together, but nothing about the materials you must use for it to work or the printer you need to employ. It's highly irresponsible, but there are plenty of fools who will jump at the chance to have a go."

However, despite the potential dangers of firing a printed weapon, Philip Boyce said people "definitely should worry" about the prospect of gun plans being available online: "Normally criminals can only get converted blank-firing pistols. But if they have plastic weapons they can get a few shots off, which is all they want."