Youtube user TopCityGear has really gone all out in this PVC Nerf Air Gun project. A used cordless drill provides the ergonomic handle for the gun, the trigger of the drill activates a sprinkler solenoid which releases the air and propels the projectile down range. I have always been surprised how well sprinkler valves work with high air pressures since it isn’t what they were designed for. The video goes through the build process which uses off the shelf PVC plumbing parts. To skip to the demonstration go to 8:25.