1/2" cpvc coupler.
Atleast an inch of cpvc, plus whatever length you want your barrel to be
Ok, there's not much there. I got the coupler for about 40 cents and an ACE hardware.
So here's what we're starting out with.
Open 'er up and you see these fairly simple internals. Note that the spring should be pressed against the plastic part at the end of the plunger, not out there where it is in the picture.
Ok, so pull out the plunger tube, take out the plunger and spring, and put those to the side.
Cut along the blue lines
The piece in between the blue lines is the one we won't need. You can put that aside or throw it away.
Grab some pliers, and pull out what's left of the air restrictors. They should look like this, or similiar once you're done.
Next is the tedious part, take about an inch or 3/4 of cpvc and sand the hell out of about half of that piece until it can fit into whats left of the barrel that's attached to the plunger tube. I recommend you keep it attached to the bigger part of the pipe while your sanding it, and cut it after, it makes it easier. This took me a good 20 minutes of sanding, and then I chipped away at it with scissors (I can't find my exacto) until it could fit into the barrel. You want about half an inch in the barrel, and the rest should be big enough that it can fit in the coupler without sliding out. Cover the bit going into the barrel with glue, and stick it in there and let it dry. It should look like this at the end.
Then, take the end that's not glued in, lather that with more glue, and pop the coupler onto that. Wait for that to dry. Here's what you should be looking at.
OPTIONAL: Wrap the plunger head in a layer of E-Tape, it makes it a lot more airtight. It will make it so it can kind of vacuum load a dart, and it will shoot further. Use two layers of E-Tape, three is a bit too much. Here's the completed plunger.
NOTE: do not have the tape cover the back of the plunger, where it catches, like in this picture. This will make your gun either not catch, or fire when you don't pull the trigger.
Now, to finish things up, put the plunger back in, and then put the plunger tube back into the shell.
Now put this piece that I had you saw off earlier back into it's place.
One end should stick out of the shell of the gun. There might be some space between the coupler and this piece, but as long as they're lined up you should be fine. This is optional, but it makes the gun look stock. Here is my gun with all the pieces in the right places.
Close the gun back up, and I put a heavy rubber band on it, and this is the final product.
You can put a cpvc barrel into it, and stick it in the coupler. This way you can expiriment with breeches, longer barrels, speedloaders etc. When it doesn't have a barrel in it looks 100% stock.
Here it is cocked, with a 4" barrel ( a few inches are inside the gun) and banded.
You can now put whatever you want on it to help cock it, like a key ring or zip tie or whatever.
I only had time to range test it once, and I was surprised. shooting a sonic micro flat from waist level, I got 64'. EDIT: this was with a 4" barrel.
EDIT 2: I'll do a full range test tomorrow probably.
Edited by Wisp, 22 May 2009 - 08:08 PM.