Yes, the world’s first 3D-printed stainless steel gun has a rifled barrel.
Eric Mutchler of Solid Concepts got back to me with answers to how the barrel of this 3D-printed gun was made. The printed into the barrel; the lands and grooves were not added later with a button or mandrel.
They did do some touch-up work after printing it to smooth and de-burr the barrel.
“The barrel was grown standing up in the ‘Z’ direction then stress relieved,” explained Mutchler.
“It is 17-4 stainless and has not been heat treated. We wanted to test our least strongest option first. We still have heat treatment options then Inconel 625 or 718 super alloys to try if this shows any indication of failure.
“The barrel was cleaned up with our rotary hand tools only. We ran an abrasive ‘flapper’ tip with sand paper to smooth the machine finish and allow a smooth bullet seat in the chamber. The lands and groves are as machined. The feed lip has been polished to a mirror shine.”
Here’s the video of the gun being test-fired in case you missed it.