This is a 3D printed, plunger-activated, 6-Dart, Nerf grenade that uses
MadBull SS6 Airsoft Shells with CO2/GreenGas.
To complete the build, you'll need the 3D printed parts and: (1) M4x5mm hex head screw, (1) MadBull Airsoft SS6 Shell, the tips from at least (6) Nerf Elite darts, and Green Gas or CO2 to charge the Airsoft SS6 Shell.
The video that shows testing, design changes, and assembly is available at: https://youtu.be/-EZONU1vb0Q