It’s safe to say that one of the most controversial topics in the 3D printing world – if not the most controversial – is that of 3D printed guns. Guns in general are a hot-button topic in the US especially, and the fact that 3D printers have made it possible to make your own functional firearm at home has some people very concerned. While the threat of 3D printed guns may be somewhat overblown, authorities have expressed a lot of apprehension about the potential for terrorists and criminals to take advantage of the DIY technology and readily available files.

One of the worries people have is that because most 3D printed guns are made from plastic, they can more easily slip through security in airports. It’s a fair concern – particularly after a report from the Department of Homeland Security last year showed that the TSA was failing to prevent prohibited items from passing through security 95 percent of the time – but a man with a 3D printed gun didn’t get very far at Reno-Tahoe International Airport last week.

According to a TSA blog post, 68 firearms were discovered in carry-on bags across the US last week. One of those firearms was a 3D printed revolver loaded with live ammunition. The man packing the weapon wasn’t cited or arrested; when security asked him if he wanted to check the item, he chose to surrender it instead.

Was the man intending to do harm with the 3D printed pistol? Or did he just forget that packing a gun in a carry-on bag is a bad idea? Surprisingly, it seems as though many air travelers are unfamiliar with TSA regulations, as evidenced by the 67 other people who had guns in their carry-on luggage last week – not to mention the other weapons and weapon replicas that are regularly confiscated by the TSA.

“In addition to all of the other prohibited items we find weekly in carry-on bags, our officers also regularly find firearm components, realistic replica firearms, bb and pellet guns, airsoft guns, brass knuckles, ammunition, batons, stun guns, small pocketknives and many other prohibited items too numerous to note,” the TSA states.

While that may seem alarming, the TSA also reassures that just because someone has a weapon in their carry-on isn’t necessarily evidence of a nefarious plot.

“Just because we find a prohibited item on an individual does not mean they had bad intentions; that’s for the law enforcement officer to decide,” the agency continues. “In many cases, people simply forgot they had these items.”

I can’t imagine forgetting that I had packed a gun or brass knuckles, but the point is that just because an item is plastic doesn’t mean that it’s undetectable. The concern expressed by the Department of Homeland Security report was less about passenger and luggage screening methods and more about better vetting and training of security workers at airports. In my experience, airport screening technology misses very little – I’ve been pulled aside for forgetting to empty a water bottle in my carry-on bag, and more than once because the bunched-up lining in my jeans pocket showed up as an area of concern on the body scanner.

Now, if the only method of screening in a secure area is a metal detector, that’s a different story, but on an X-ray machine, the outline of a 3D printed gun shows up just as clearly as that of a metal gun – or a water gun, for that matter. Guns may be transported in checked baggage if they’re unloaded, properly packed, and declared at check-in; the TSA also reminds people to familiarize themselves with local gun laws wherever they’re traveling.

Another issue that concerns security agencies is that 3D printed guns can be dismantled and reassembled after passing through security; in 2013, two Daily Mail reporters tested security at St. Pancras International Station by 3D printing a gun using the Liberator files posted online by gun advocate Cody Wilson. They were able to easily get through screening with the various parts of the gun concealed in their clothing; once on the train, they assembled the gun in minutes. When the story broke, it horrified security experts and prompted politicians to call for improved screening measures in public transportation. Agents also managed to get 67 out of 70 weapons and fake explosives past TSA in a US security test, which led to further concerns.

Authorities are uncertain where the files for the gun confiscated at the Reno airport came from; a search of 3D printable gun files posted online turned up nothing that matched the gun the passenger was carrying. It’s possible he may have designed it himself. Discuss further over in the 3D Printed Gun at Airport forum at 3DPB.com.

Please enable JavaScript to view the comments powered by Disqus.