A fully automated, integrated, end-to-end synchronized and compact manufacturing system produces polymer or metal case ammunition. Manufacturing stations support case assembly, sealing (gluing/welding), final product inspection, cartridge packaging or binning, and loading. Station modularity facilitates rapid changeover to accommodate ammunition of differing calibers. Sensors and apparatus may be provided to place a manufacturing cell in a wait state until all components or materials are received in a preferred orientation for proper assembly. The system may join and use multipart cases, each including a lower portion with a head end attached thereto and at least one upper portion having a necked-down transition to the open top end. Elevator feeders, vibratory bowl feeders, and robotic pick-and-place feeders may be used to deliver components for assembly.