If you haven't already, do yourself a favor and follow the Transportation Security Administration's Instagram account. In addition to the intermittent photos of adorable bomb-detecting dogs, you'll also see a bunch of illegal items the TSA confiscated from unwitting airline passengers.
Some are pretty typical (machetes, ninja stars, mummified head, etc.). Guns and firearms, which are allowed in checked bags but not carry-ons, also make a large part of these items. However, at the Reno-Tahoe International airport, the TSA confiscated a gun created from a 3D-printer, and it was loaded with live ammunition.
"The passenger was offered the option of checking the item in carry-on baggage," said the TSA in a press statement. The passenger, however, "elected to leave the item behind with TSA." He then continued onto his flight and "there was no impact to airport operations."
The first 3D-printed gun debuted back in 2013 and was seen as an inevitability once 3D-printers became more accessible to the mainstream market. While some argue that the fear of 3D-printed guns is overblown, they're still a point of contention. They cannot be detected by x-rays and metal detectors, but they can successfully fire off several shots.
The 3D-printed gun was included in the TSA's weekly roundup between July 29 and August 4, 2016. During that time span, the agency discovered 68 firearms (including the revolver) -- 59 of which were loaded.