Cut a piece of 1/2" PVC. The length will vary on your barrel length. Mine is about 9".
Cut your dart port. This will vary in length and location depending on your blaster and dart length. My port is about 2" long.
I also rounded off the edges with this cone bit on my dremel.
Now get .5" of 19/32, .5" of 9/16, and 1" of 17/32. You can substitute e-tape for the 9/16 and 19/32, but I had extra brass laying around and like the support.
Super glue them together so the 9/16 and 19/16 are together and the 17/32 is half-exposed.
Add e-tape around the 19/32 to fit snugly into 1/2" PVC.
Super glue this piece into the back of the breech. I only applied super glue to the electrical tape and then shoved it in to prevent super glue from getting on the 17/32. Super glue on the 17/32 would negatively effect the PETG seal.
Get a piece of PETG (mine is 12") and wrap some electrical tape around to fit a piece of PVC on to. *This will also vary in length depending on your other piece of PVC's length and the length of the PETG. Mine is 2.5" long
Super glue the PVC onto the PETG.
Add electrical tape at various point in the PETG for stability in the PVC. This doesn't need to be air tight or cause resistance.
If you choose not to add the string, this is finished.
Get a piece of string and burn the edges to prevent fraying. My string is 11" long.
Secure the string to both pieces of the breech with electrical tape.
This will prevent the barrel from coming out of the breech. There isn't as much friction on the barrel as there would be in a brass breech, so this could be a problem without the string.
This is the finished breech in my BBBB.
I have no difference in range compared to my normal PETG barrel. I really like how easy it is to use, and the seal from the PETG to 17/32 brass is great.
*The string is really only needed if you put the dart port so far forward like I did. I only put it there because this breech is only for my non-minimized BBBB. If you put this on an exposed coupler, there should be enough room in the PVC for the barrel not to slip out. I won't be making any more of these though, so I won't be able to test it. (I think breeches are lame in general and speedloaders/turrets are much more efficient)
Edited by Coop, 30 August 2009 - 01:26 AM.