First, don't post a separate thread for your paint job. Put it in the mods and PJ thread. Second, If you upgraded your seal, there may be too much friction for the stock spring. Also, stretching your springs weakens it over time. Did you relube the o-ring when you replaced the plunger tube?
Yes, I relubed ththe o-ring, the spring has stayed streched, and the reason I will be putting the paint job in another thread is that I have a whole new color scheem spanning mutiple blasters and this is a problem with a specifec blaster.