it's a lot bigger than it appears
the double A batteries are not to be shot at anyone
so lower the pressure if you are going to shoot it at someone. and not at their face
Step 1: Materials
1-1 inch PVC pipe (8 feet standard I believe)
2-1 inch end caps
1- tire replacement valve (auto parts store)
2- 1 inch, 45 degree angled elbows
1- 1 inch T valve
1- 1 inch elbow
1- 1 inch non threaded/threaded 1/2 inch adapter (elbow)
1- 1/2 inch threaded pipe (6-8 inches, depending on preference)
1- 1/2 inch threaded pipe (14 inches long, or how ever long you need your barrel
1- 1/2 inch threaded on both sides ball and socket valve
Silicone (optional for leaks)
Bike Pump W/ A GAUGE! (a compressor just doesn't work very well)
Pen ( To mark cuts)
Step 2: Measure your Piping
Next, cut a piece of the 1 Inch piping that long.
A)Cut 1piece of the 1 inch PVC about 2 inches, just enough so it connects the vertical elbow to the T valve.
B)Measure how far you want the first compression chamber to connect to the T valve.
C) Take the same length PVC (B) and cut one the same (or a little more) length to connect the top compression chamber.