Automatic Grenade Launcher (Airsoft/Paintball/Nerf)

[jackssmirkingrevenge]

Nice idea, although in my mind a semi auto would be more efficient. As far as feeding goes something like a blow forward bolt but with some modification could allow both semi and automatic modes.

With this design, slight pressure on the blowgun should give you a single shot capability.

May want to go larger orifice valve at lower pressure and size the chamber for a positive pressure on projectile exit. To pull it off may require designing and building your own low pressure pop off valve.

Good points, though you can buy adjustable relief valves.

[Davidvaini]

I would be using it relatively lower pressures. I think around 120 psi if not a little less.

Those plastic balls may collapse at 120 PSI with a fast valve. May want to go larger orifice valve at lower pressure and size the chamber for a positive pressure on projectile exit. To pull it off may require designing and building your own low pressure pop off valve.

they are not plastic, the ones I'm using are foam.

As far as the hopup is concerned it will help on keeping the projectile stable and far more accurate. I used the same nerf balls in this video: