Plastic is nice but this is the direction for future manufacturing ATM. When the “corner” machine shop / store can make anything you want then it is the end for control freaks. The following description is from the company that makes the machine:
Additive Manufacturing (AM)
Additive Manufacturing is the process of producing parts by successive melting of layers of material rather than removing material, as is the case with conventional machining.
Each layer is melted to the exact geometry defined by a 3D CAD model. Additive Manufacturing allows for building parts with very complex geometries without any sort of tools or fixtures, and without producing any waste material.
Hence, choosing an AM technology for production provides great benefits for the entire production value chain. The geometrical freedom allows you to engineer/design your part as you envision it, without manufacturing constraints. This can be translated to extreme light-weight designs, reduced part counts or improved bone ingrowth for a medical implant. It is also a fast production route from CAD to physical part with a very high material utilization and without the need to keep expensive castings or forgings on stock.
In addition to its cost-efficiency Additive Manufacturing is, due to its high material utilization, a very energy-efficient and environmentally friendly manufacturing route.
http://www.arcam.com/technology/additive-manufacturing.aspx
I never said that it was not expensive now but in with future iterations of this or similar systems anything can be made. “Easy Bake” weapons but chroming the barrel and other processes will still be needed.