I've tested it up to 5X and it's loud but the damage isn't too impressive. Again due to leaks and my syringe.
I have a feeling that some air is leaking through the wires and my shock pump's check valve is messed up causing it to leak slightly.
Specs:
Chamber: 15mm copper x 10.8cm
Barrel: 8mm OD 6mm ID of aluminium. No idea of the length, probably about 15 inches.
Burst disks: Sheets of packaging plastic.
That's about it.
The whole gun with the piezeo attatched:

Close-up of the chamber:

Looking down the barrel which is a 1/2 to 1/4 inch bushing with the barrel glued it.

The rubber washer in the 1/2-15mm female straight:

Damage, Top one is a .25g BB and the bottom one is a .22 Bisley practice pellet with the skirt widened.
