This thesis explores the potential of pellet-based fused granular fabrication (FGF) for the production of injection molding inserts, focusing on the transition from filament-based fused filament fabrication (FFF) systems to pellet-fed 3D printing with the Piocreat G5 PRO. Unlike conventional filament approaches, FGF eliminates the intermediate extrusion step and allows the direct use of compounded or recycled feedstocks, offering significant reductions in cost, lead time, and material waste. These advantages make pellet extrusion particularly attractive for rapid tooling, prototyping, and small-batch manufacturing where flexibility and speed are critical. The research establishes a complete FGF-based workflow for producing polymer–metal composite inserts, validating the capability of the G5 PRO system to process both commercial polymers in pelletized form and newly developed materials.