Powder feed cylinder assemblies and powder feeders are provided. A powder feed cylinder assembly includes a cylinder, a bit, and bushings. The cylinder has a main passage, a first feed channel, and a second feed channel, each feed channel at two axial locations between the cylinder's two ends. The bit extends through the main passage and has an outer surface including a helical channel formed thereon. A center bushing is disposed in the main passage between the two axial locations and has a first axially-extending passage through which the bit extends. The first end bushing is disposed in the main passage on one side of the center bushing and has a second axially-extending passage through which the bit extends. The second end bushing is disposed in the cylinder on the other side of the center bushing and has a third axially-extending passage through which the bit extends.