|A build platform of Salen Compensators (Image source: The Firearm Blog)|
When printing in plastic, support structures are normally only for supporting the geometry of the part. But with printing in metal, support is often used to provide stability across the parts of the entire model; otherwise some warping can occur as smaller and thinner parts cool faster than larger areas, leading to deformation.
3D printing can be used not only for manufacturing, but for cheaper and faster prototyping and to open new doors. For example, 3D printing in metal can be used to create suppressors in strange, nontraditional shapes like those shown below. These are shapes that would be impractical or impossible to create using any other method. In the image shown, the barrel of the gun goes into the hole on the left. The bullet exits from a hole inside the "wedge" on the right.
|Unusual design firearms suppressors 3D Printed in metal. The top is a centerfire suppressor, the bottom for rimfire. (Image: The Firearm Blog)|