[lepton]

It takes more than just sintering it together to make those things. That said, it also looked to me that there were little voids in that picture - though that could be just the surface ripples.

[null and void]

Hmmm, I didn't know if it had ever actually been fired, just using the graphic as eye candy.

BUT, now that you ask, according the the source of infinite knowledge - Wikipedia:

The Solid Concepts 1911 DMLS is a 3D-printed version of the M1911 pistol. It was made public around November 2013 and was printed via the direct metal laser sintering (DMLS) method. It was created by Solid Concepts. A Solid Concepts Browning M1911 replica fired more than 600 rounds without any apparent damage to the gun. The metal printer used to create the weapon cost between $500,000 to $1,000,000 at the time the gun was created as of November 2013. The first gun, version 1.0, is made up of 34 3D-printed 17-4 stainless steel components.
...
The Solid Concepts Pistol fired its 5000th round on 6 September 2014.

Thanks for asking!

More eye candy:

The Solid Concepts 3D printed 1911 pistol

Looking from the “Chamber end” of the Solid Concepts 3D printed barrel

The ability to place text inside the barrel is possible with 3D printing

All images courtesy Solid Concepts, Inc.