
Here's the first part.

Thats it!
Edit: Unfortunately, photobucket resizes the photos.
What I did, was I cut a breech in the barrel. Then I cut a breech in come pvc coupler, the same size. I put that over the barrel. Then I attached the clip, a little past the coupler. When I twist it, theoretically, It should force a dart into the barrel. Then twist and fire.