The first metal gun made on a 3D printer has been unveiled, with a video showing the firearm being successfully tested.

The gun comprises more than 30 3D-printed components, including stainless steel and other metal parts.

In a blog, Californian engineering company Solid Concepts, said: "It functions beautifully. Our resident gun expert has fired 50 successful rounds and hit a few bull's eyes at over 30 yards (metres)."

But the firm said making the classic 1911 pistol did not come cheap, requiring a lot more than a souped-up desktop printer.

Vice president Kent Firestone said: "This isn't about desktop printers ... the industrial printer we used costs more than my college tuition - and I went to a private university."

Solid Concepts said its system is legal, claiming it is the only 3D printing service provider with a Federal Firearms License.

The company said: "Now, if a qualifying customer needs a unique gun part in five days, we can deliver.

"We have the right materials, and the right engineers who know how to best programme and maintain these machines, to make 3D printing accurate, powerful and here to stay."

The use of 3D printing technology to manufacture weapons is not new, but making them out of metal is.

Earlier this year, computer files allowing someone to make a single-shot Liberator gun were downloaded more than 100,000 times from Defense Distributed, an open-source website dedicated to 3D printable gun components.

The State Department, which oversees US weapons exports, ordered the blueprints to be taken off the internet in May, but by that point, users had already reposted them widely on various file-sharing sites.