New semi auto chamber design:maybe full auto later

[upit14]

Hi, Ive had this design, in my head for at least a year now, and Ive finally found the parts I need for it. I would be very grateful for any comments on how I can improve it. The Expansion chamber will be made of 5 mm thick PVC that has two seals on the outer rim of the PVC piston.
Almost all the internals will be made of copper.

[upit14]

I found every piece I need at home depo, Im thinking it can stand maybe 90+ psi

[quinn whitsitt]

nice work could use some improvement though still but then again any spudgun can never be good enough to be the ultimate spudgun