Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
Indeed it is being held in by only that tab of pvc pipe, however the force on the piston is quite small and i trust it entirely.
I have also experimented with tapping it off of the tab while at full pressure, the piston barely has enough force to overcome its own friction and only juuust reaches the end outer limits of its stroke.
The metal circle on the lower pvc sleeve is a high tensile pin, holding a solid machine grade aluminium plug inside the pipe, which holds the pump center and also retains it securely inside the tube.