This gave me an excuse to experiment with it. So I attempted to single it by making a replacement plunger/barrel for it. I made one out of 1/2 SCH80 pipe by lathing down the outside diameter then adding a groove for the O-Ring and a stop to prevent the dart from being sucked into the plunger chamber.
The seal was so perfect that the plunger was maintaining a vacuum when drawn back. So I had to add a divot to the o-ring groove to allow the o-ring to deform under vacuum pressure, allowing the plunger chamber to equalize.
To make the plunger easier to draw back now that there is no slide or bolt, I added a handle to the back of the plunger tube.
I then made a frame piece to hold the plunger/barrel in place and to act as a stop for the plunger tube when firing.
End result looks bizarre and unfortunately performs terribly. Shoots at best around 25 feet.
I'm not sure whether to blame the poor performance on the tightness of the plunger seal, the weakness of the spring, or the length of the barrel. But basically I gave up because I started feeling crappy.
Later this week I'll probably take the plunger/barrel back to work with me and drill out the center so I can nest a PETG barrel in it. That will give me more control over the functional length of the barrel.
Edited by CaptainSlug, 01 April 2008 - 07:36 PM.