by Moondog
Watch the YouTube review:
http://www.youtube.com/watch?v=3sGOuUkzXss
When upgrading the spring on your gearbox, you may find that your FPS hasn't increased as much as it should. Which means you've got an air leak. And a common place where this occurs is the air nozzle.
The best way to fix is this by replacing your stock nozzle with one with an o-ring
like the Matrix air seal nozzles made by Guarder.
What makes airseal nozzles different is that there is a tiny o-ring inside, that really makes the seal with the piston head, air tight.
How much of an FPS difference does this make?
315fps = Stock ARES Tavor
333fps = PDI-190 sping upgrade and stock nozzle
372fps = PDI-190 spring plus air seal nozzle
That's over a 30fps increase with the same spring!