Nearest workshop for me is a CNC shop called Acme Machining and Welding that work on stuff for oil rigs, so if I took the piston there they wouldn't even take it.
I have tried to find a gunsmith who would let me do it but again no dice.
The piston seal doesn't have too be 100% airtight. The...
Alright, of all things, this is going to be used on a high-flow, quick opening outlet sealing valve, made for a recreational "toy"...
O-rings are, first off, the most obvious choice for a moving, (non-static), seal. But they usually require an accurately machined O-ring groove for them to...