This deal includes 3D printing filament, nozzle and hotend kits, and soft magnetic steel plate. For fast and precise printing, I really like the Elegoo Neptune 4 Pro (see our review here).
It was a single-shot pistol made with Fused Deposition Modeling on a Stratasys Dimension SST 3D printer. The Liberator is close to being a wholly plastic gun, although it still requires a steel nail ...