First of all I do not want to take any credit for thinking up this idea. I heard about the idea in this thread from Matt Dublak
In order for your bolt to work, it uses a source of air to get moving. This source comes from your solenoid. The amount of air coming from your solenoid is changed by adjusting how long your solenoid stays open. This is called the dwell. The lower the dwell, the more efficiant your gun is. If your dwell is too low then the bolt won't be moving with the right amount of force and the paintball will just fall out of your barrel or not come out at all. This is called drop-off. With the use of a spring set behind your bolt, you will have the ability to dramaticly lower your dwell without experiancing any drop-off. This will work with sft and nxt shockers. Using the exact spring you see pictured, I lowered my dwell from 13ms to 8 ms.
You will need an alan key to remove the bolt guide, something to push the bolt out with (the cayola marker), and the spring
My spring is 3 cm long and about .8 cm wide. the length is probly the more important measerment. When the bolt is all the way forward, the spring should still be touching the back of the bolt tip and the bolt guide. Make sense? I tryed springs that are shorter and they don't work nearly as well. The width isn't too important, but make sure the spring isn't touching the sides of the bolt, because it will scratch the bolt.
Here is the spring
Unscrew your bolt guide and push out the bolt
Take the Bolt (the firing can will be atatched it you have the HE bolt)
Drop the spring down the back side of the bolt
This step is not neccecary, but I am doing it to show you that the bolt will sit up higher than usual on the bolt guide
Take the bolt guide back off and put the bolt sleeve on
Put the bolt guide back in
Put the bolt system back into the Shocker. It is normal to feel resistance from the spring
And you are done with the mod! But remeber you still have some adjustments to do. You can lower the dwell now, and you may have to lower the hpr too, because your gun may be shooting hot.
You may be able to use different types of springs. The one you see here works great for me. If you do the mod, feel free to post your new settings and how it worked for you. Here is what my gun is set at right now
Hpr (cp reg)- 185 psi
dwell- 8 ms
Bolt - HE with spring Mod
Velocity- 278 fps
Anti bolt stick- 1
Eficciancy (from 45/4500 tank)- about 1000 shots per fill