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.
STL file Nerf gun wall mount・3D print design to download・Cults
Nerf Rival Charger Full Auto Seer 3D model 3D printable | CGTrader
nerf" 3D Models to Print - yeggi
Free Nerf 3D Print STL File Mods - Andy Maker
Quik 3d Printed Fully Automatic Flycore Toy Nerf Blaster .STL - Etsy
HECATE - Rear Load Inline Nerf Bigshock by Mighty Shrub | Download free STL model | Printables.com
Super SPAMF Toy Nerf Blaster Falconfire Mod Kit .STL Files - Etsy