A group of 3-D printing gunsmiths have taken another step toward making a gun you can download off the internet. This weekend, the desktop weaponeers took a partially printed rifle out to test how long its plastic parts survived spewing bullets. The result? Six rounds until it snapped apart.

But that was also the point, the group's founder tells Danger Room. "We knew it would break, probably," says Cody Wilson, who heads the Wiki Weapon project. "But I don't think we thought it'd break within six [rounds]. We thought it'd break within 20."

It's the first live testing done by Wilson and Defense Distributed, the online collective that aims not only produce the world's first fully 3-D printed gun, or "Wiki Weapon," but create a clearinghouse for sharing weapons blueprints over the internet. But until these early prototypes can fire more than a few rounds without breaking, they have to be tested. The pressure from firing rapid-fire rounds is still too strong, though slowly firing single shots has apparently been demonstrated to last longer.

The gun tested this weekend was not fully 3-D printed, only partially. The only printed part was the lower receiver – or the gun's trigger and grip – for an AR-15 rifle completed with off-the-shelf metal parts, which was first developed by Wisconsin-based engineer and hobbyist Michael Guslick. And the design works, technically, but is still far inferior to a standard rifle.

But Wilson learned a few things about how to improve it. For this weekend's test, Wilson's best guess is that the force of recoil destroyed part of the plastic lower receiver, causing it to come unhinged.

Wilson first fired one round to see if the gun worked, and then handed it to another member of the group. With 10 rounds in the magazine, the shooter managed to unload five. The recoil "pushes the ring back and down," Wilson says, referring to the o-shaped ring attached to the gun's upper receiver – which cycles the bullet – and shoulder stock, creating tremendous stresses.

One potential solution is reinforcing the o-ring, which the group detailed in a blog post. This might be done by just making it thicker, with more plastic material added to the ring's sides where it won't interfere with other components. The group also wants to reshape the trigger guard, boost the strength of interior pins and bolt bosses, and include custom markings – such as whether the gun is in the "safe" position – along with the printed product instead of laser-printing the markings afterward.

"We've been talking about this for months, so this is just a way of releasing some steam and doing something fun," Wilson says. "We've been really heavy on the talking side of things, but we really just want to do things, you know?"

For weeks, they haven't been able to even start. In September, Wilson leased a 3-D printer from additive manufacturing firm Stratasys that he planned to use to make the weapon. But it didn't work out so well, at first. Stratasys' legal representatives, after getting wind of Wilson's plans – and citing the "Undetectable Firearms Act," which outlaws plastic guns that can defeat airport security scanners – revoked the lease and promptly seized its printer back.

That stymied Defense Distributed, but it didn't exactly stop them. Since losing their Stratasys printer, Wilson says he's received help from two unnamed companies based in Austin and San Antonio, where his group can print and test their guns, and is waiting on a federal firearms manufacturers license, as the Undetectable Firearms Act provides an exemption for plastic gun prototypes designed by licensed manufacturers. (Stratasys does sell printers to licensed firearms manufacturers.) Wilson has also since incorporated Defense Distributed into a nonprofit corporation.

But another reason Defense Distributed ran into trouble is the group's public nature, and their plans to distribute printable gun blueprints. That has gun control advocates worried. While Wilson's group plans to print their gun officially, the same likely won't be true for potentially anyone with a 3-D printer – which are becoming increasingly common – along with a few hours to spend downloading a gun off the internet.

The other question is whether you'll be able to print a working gun, or a gun that can be used outside of testing it until it snaps apart. For now, that's unsettled. But printed guns are becoming a reality, and they're likely only to get better.