The FG 42 is arguably the coolest machine gun ever. This is a 1:1 prop model, with moving bolt handle and trigger. The magazine is detachable. Rubber bands or springs are required if you want operational bolt handle and trigger.
All parts can be assembled and disassembled using M5 screws that will self tap into the print. The only part that needs a tiny amount of glue is the rear sight assembly.
Additional hardware needed:
1x Pipe/rod 18mm OD x 800mm length. For the barrel (I used a copper pipe).
15x M5 x 15mm screws. For main assembly.
2x 3.0mm x 12mm wood screw (Alt M2x16mm with nut). For assembly of sights.
2x Rubber bands or springs for trigger and bolt handle.
Recommended PrusaSlicer profile: 0.20mm SPEED, 20% infill and supports (on build plate only). This will use ~1kg PLA total.
Printer bed size requirement is ~25x21cm (Prusa MK3).
Video of moving parts: https://www.youtube.com/watch?v=A3TW7QKMLRg
The author hasn't provided the model origin yet.