3D-printed firearms are back in the spotlight after a US company re-published blueprints allowing anyone to create a DIY pistol in the privacy of their own home - so should Kiwis be worried about these "ghost guns"? LUKE APPLEBY investigates.
Five years ago in 2013, Texas company Defence Distributed, headed by Cody Wilson, designed, built and fired the first 3D-printed gun - the Liberator - before releasing the blueprints online free to anyone who wanted them.
Two days later, they were ordered to take the plans down by the US Department of State, saying they had a duty to oversee the export of technical data related to firearms.
Several US politicians have vehemently opposed the weapons, arguing that giving out untraceable gun blueprints could enable terrorism or increase gun violence.
Last month on July 19, Defence Distributed reached a settlement with the Department of Justice which barred them from giving away their plans - but technically did not stop them being sold for a price from August 1 onwards.
A day before they could start selling the plans, which they planned to do on a "name your price" basis, a federal judge stopped the release of the blueprints once again, citing safety concerns.
US President Donald Trump tweeted on August 1 that he was "looking into 3-D Plastic Guns being sold to the public", adding that he "already spoke to the NRA," and that 3D printing a firearm "doesn't seem to make much sense".
Last week on Wednesday, NZT, Defence Distributed began selling the blueprints anyway, saying they think they are within their rights to do so.
The blueprints have also been widely shared and re-hosted, and are currently available on numerous websites for free.
IS IT ILLEGAL TO DOWNLOAD THESE BLUEPRINTS?
The short answer no - there are no specific laws in New Zealand against downloading a 3D gun blueprint - but it is definitely illegal to manufacture and possess a firearm without a licence.
It also remains very difficult for someone to procure the .380 bullets needed for a Liberator, as those are controlled under the Arms Act in the same way that firearms are, with numerous checks and safeguards in place.
A police spokesperson told 1 NEWS they believe the current Arms Act restrictions on importing pistol parts without a permit could apply to 3D-printed firearm blueprints - but only if interpreted in a very specific way.
"If downloading is considered as importing and the parts of a 3D firearm are downloaded, the moment a part for a pistol or restricted weapon is downloaded an offence has been committed," a police spokesperson said.
Police's rationale rests heavily on the downloading of a file being considered, legally, as the importation of a good, and on the judge considering digital plans for a firearm being a tangible "part" of the weapon itself.
Police also referred the issue to the New Zealand Customs Service, who told 1 NEWS that "under the current provisions of the Customs & Excise Act, a 'data file' containing a digital model to print out an object using a 3D printer is not a "good".
"The 3D printing data file can be compared to a JPEG file to view and print out a picture."
Firearms lawyer Nicholas Taylor, who has 20 years' experience litigating cases involving guns, said he was confident charges brought against someone for downloading the blueprints under the Arms Act rationale would never be upheld in court.
Mr Taylor said it was "too far removed" to consider the plans for a firearm as an integral "part" of a firearm itself.
"It's ridiculous to say that their possession will constitute possession of a restricted weapon part ... it's ludicrous," Mr Taylor said.
"A 'part' is obviously an objective test, but everyone knows what a part is of something - it's something tangible instead of the intangible."
In response to the rise in availability of computer fabrication and 3D printing technology, New South Wales passed a law in 2015 making it a specific offence to be in possession of digital weapon blueprints, with a maximum penalty of 10 years in prison - in line with the penalty for being caught with an actual firearm.
An NZ Police spokesperson said they are "aware of the commentary around 3D firearms and is monitoring developments in this area.
"Firearms technology has changed and Police will continue to administer, and as required, enforce the Arms Act," they said.
"Anyone in New Zealand having possession of a firearm must have a firearms licence or endorsement, or be under the immediate supervision of a licence holder."
IS IT CHEAPER NOW TO 3D PRINT A GUN THAN FIVE YEARS AGO?
The original Liberator was printed on an expensive Stratasys Dimension SST 3D printer, costing about NZ$50,000 in 2013, but the same machine now costs anywhere between NZ$8000-NZ$10,000 for a used unit - an 80 per cent reduction in price.
However, amateur 3D printers technically capable of printing a Liberator out of ABS plastic are now available for less than $300.
Zubbin Navroji of 3Dprintingservices.co.nz, who is also an avid target shooter himself, said while people could print a Liberator on a $300 machine, the quality would be lower than on a more expensive machine.
Mr Navroji said the inherent weakness of a 3D-printed object made on a home machine comes from the "layer by layer" construction method - a weakness which has not been considerably resolved since 2013.
Firing a round puts immense - and dangerous - strain on a 3D-printed gun's parts, Mr Navroji said, and plastics technology in the past five years has still not quite overcome that strength barrier reliably, despite the big drop in average price.
"Plastic as a material is not suitable [for gun-making] and 3D-printed plastic and polymers in particular are not designed to handle such pressure," he said.
"You will basically blow yourself up or hurt others around you."
The technology is still advancing rapidly, he said, with affordable home printers capable of using media like resin likely to be the next step - those would allow a much higher quality finish and better strength.
Metal 3D printing does exist, and is also a rapidly developing field - Texas company Solid Concepts this year built an entirely metal 3D-printed pistol and it has fired more than 600 rounds without issue.
The lowest-priced 3D metal printer currently available is very large, costs upwards of $180,000, requires a three-phase power supply and uses multiple industrial gases.
IS A PLASTIC FIREARM SAFE, OR WILL IT BLOW UP IN YOUR HAND?
Apart from the projectile coming out the end, firing a plastic firearm comes with risks to the user.
Videos of 3D-printed Liberator pistols being fired show they can fracture easily and unexpectedly, sending shards of plastic flying in all directions.
Many of the Liberators which have been printed and test-fired with a .380 round have fractured after just one shot, while others have survived numerous rounds being fired through them.
The pressure exerted on the barrel of a gun while firing a .380 peaks at about 21,500psi according to the US Sporting Arms and Ammunition Manufacturers' Institute.
ABS plastic has a typical tensile strength of about 5800psi - and that doesn't account for the extra weakness introduced by 3D printing's layer-by-layer construction.
Last year, hobbyists tested a process called "annealing" on 3D printed objects - this involves heating the object in a home oven to "glass point" then letting it cool very slowly as one uniform piece.
Annealing can reportedly help relieve the internal stresses, weaknesses and fracturing caused by the uneven cooling of the plastic during the printing process, and proponents say it improves the strength of objects considerably.
In 2014, Pennsylvania machinist Michael Crumling designed and built bullets specifically designed for the Liberator, which he called ".314 Atlas" rounds.
Atlas rounds have a much thicker casing than usual, as well as a lead projectile inserted deep inside the casing, somewhat like a cannon, rather than sitting on the tip of the casing.
The design mitigated all of the pressure of the explosion, channelling it out of the barrel - Crumling successfully fired 19 rounds of the custom ammo through a Liberator he had printed at home.
COULD A GUN BE PRINTED BY A COMPANY WITHOUT THEM KNOWING?
1 NEWS spoke with six Kiwi commercial 3D-printing companies about the issue, and all said they are well aware of what 3D firearm blueprints look like.
None of the companies have printing processes which are independent of human oversight at all stages.
"There is an extremely low chance of someone getting us to print something that we don't want to be a part of,' Mr Navroji said.
"We would never do it."
None of the companies had been asked to 3D print a weapon by a customer, and all said they would refuse to do so on legal or even moral grounds, if asked.