Airsporter S good and bad ?

[El Garro]

Hi Mick, was the face at the end of the cylinder concave ? That's something I've not checked yet.

I'm wondering if the thread section is damaging the seal. I've taken to screwing the piston in until the seal clears the threads to save rounding off the lip.
I'm pretty sure this is a limiting factor to how big a seal you can fit in as the cylinder internal diameter opens up past it , meaning you need to squeeze the seal through a smaller hole than the actual compression cylinder. I'd guess that if you looked at the big picture, airguns were still developing when these were built. The move from leather seals to O ring (I hate this type) to PTFE, then eventually to the parachute seals we see in nearly all production guns now. Maybe it's a waste of time trying to improve the performance of some older guns. Perhaps optimising them would be more rewarding regardless of the power produced ?
Personally, I want more though