Hi there.

I recently acquired a FAS604 pistol from an auction. On examining it, I found that the seals had perished and it wouldn't pressurize, although the trigger was cocking OK.
I replaced all the seals (including the fiddly little so-and-so inside the valve), lubed and siliconed it. It now pressurizes up, but won't cock.
I can cock it by removing the pin which secures the piston to the top frame, and lifting the whole internal mechanism higher than the normal cocking stroke. Pop the pin back in, compress the cylinder, and the gun now fires. Then it won't cock again.
I'm baffled. Anyone else had this issue, and if so, how did you fix it?

Thanks.


Air arms S410TDR, Air arms Camargue, Jackal Woodsman, Logun S-16 (in bits).