The world's first gun made almost entirely with a 3D printer has been successfully fired in the US. But it's not going to herald an age of widespread weapon ownership, and it's certainly not proof that 3D printing technology needs to be controlled for our safety.

The gun – called the "Liberator" and produced by Defense Distributed, a group that describes itself as aiming to "defend the civil liberty of popular access to arms" through "information and knowledge related to the 3D printing of arms" – is the second to have made the headlines in the past year. In July, an American gunsmith printed the lower receiver for an AR-15, a type of modular assault rifle popular among enthusiast. Although not capable of firing on its own, the part is the only component legally considered a firearm in the US, so the rest of the gun – the barrel, trigger, cartridge and so on – could be bought without a licence.

The Liberator is a more serious prospect. All of the necessary parts can be printed from a 3D printer except for the metal firing pin, which is made from a single nail. (In order to comply with US laws, the gun as produced also has a 175g chunk of steel inside it, so that it doesn't evade metal detectors). It is a fullblown gun, and recognisably so.

But technologically, it's still simple. That's because the principle behind a gun isn't too tricky: load a bullet into a reinforced tube, and whack the back of it hard. That's an engineering problem street gangs in the 1950s managed to solve with wood, antenna housings and elastic bands, building "zip guns" to shoot at each other; and it's also the basis for converted air rifles and cap guns. The difficult stuff – getting it to fire accurately, repeatedly and without jamming or blowing up in your face – is still a long way off for 3D printers. And even the best 3D-printed gun still relies on someone else to make the gunpowder.

The fuss around the printing of guns shows the real impact 3D printing will have on our daily lives. By expanding the realm of "digital" goods into the physical world, it extends the questions we've been struggling with when it comes to the internet – how to control the instructions for hacking copy-protection, encrypting files or making bombs (those last instructions apparently followed by the Tsarnaev brothers in Boston to lethal effect) – to a whole new area.

The wargaming company Games Workshop has to come to terms with 3D printing of its miniatures in the same way that Paramount Pictures and Warner Music Group are starting to acknowledge that a certain level of piracy will always be endemic.

While there are downsides for some, others benefit greatly. Initiatives like Project Gutenberg or Google's plan to scan every out-of-print book in the English language have vastly increased the proportion of human knowledge available to the average person; and if you're struggling to refurbish a century-old car, the fact that the company that made it hasn't existed for 30 years will no longer stop you from being able to print off the right part to get it running again.

Ultimately, trying to pin down whether 3D printing is good or bad is like trying to answer the same question for the internet, telephones or the postal service. Some livelihoods will be transformed, others ruined; the only constant will be the change it brings.