This is JSPB3D, part of the use of 3D printing, it is very simple production,just need to put it together , glue together, and you can change the style you want.
 
This model looks like some of the features of the past works, is not the same place? 
it has reserved some air road,using PU soft tube to connection, in addition to the RSCB Clip can be added,
the future can also connect another pump to push the clip inside darts.
 
3DSTL Files : 
JSPB3D SCH40 core.STL
JSPB3D SCH40 breech ring.STL
JSPB3D trigger.STL
JSPB3D guard.STL
Breech block.STL
lock plate.STL
 Download blaster stl file free!

3D Printr settings:
I used the layer of 0.25mm and 0.6mm of the nozzle,
Basically, this model is fairly easy to print and does not require supporting materials.
 
Specification:
In Asia to get CPVC SCH40 is difficult, here are the use of CNS specifications,
Later I ordered the HERSHY CPVC4120 SCH40 on the Internet ,so I actually tested it
 
Tolerance issues:
Too tight part can use the hammer to knock into, too loose place can increase the thickness with PTFE TAPE,
Model tube through the place where most of the design groove, you can also plug O-Ring,
There is another way is to use screws to fix.

If you like, you can also upgrade it!