This is the overall gun.

On the back is the plunger, (I'm going to diagram the whole thing farther down the page) which has a 1/2" PVC Tee fitting on it for a handle.

Here's the middle of the gun where it reduces from 2" to 1/2". The metal piece is something else I'm working on, and it has no use right now. I have a slip 2" to threaded 1/2" reducer so I can swap out barrels.

Here's the laser/light combo.

And lastly, the end of the barrel which has a larger portion because it was from the end of a 20' stick of 1/2" pvc.

I will update shortly with a diagram...
Comment!
EDIT!!! Video: