I mostly use my printers to build these. 3d printed nerf blasters. most of these files are on thingiverse. except the pistol. You'll have to buy the stl files for that one.
HECATE - Rear Load Inline Nerf Bigshock by Mighty Shrub | Download free STL model | Printables.com
Top 5! 3D Printed Nerf Blasters - YouTube
STL file NERF Elite Stock // Shoulder Support・3D printer model to download・Cults
nerf n-strike elite rough cut - 3d scan 3D Model in Toys 3DExport
STL file Simple Nerf Gun for Rival Ammunition・3D printable model to download・Cults
Hasbro: Nerf Elite 2.0 Echo CS 10 Blaster
STL file Nerf gun wall mount・3D print design to download・Cults
Nerf Rival Charger Full Auto Seer 3D model 3D printable | CGTrader
NERF ACOG-sight by Print-3D | Download free STL model | Printables.com
NERF Dart Tag Set 3D Model $20 - .stl .max .fbx .dwg .dxf .obj .sldpr .3ds .ige .dae .unknown .wrl - Free3D