I have recently acquired this pistol however it was down on power so took it apart and found the piston/nozzle seal was knackered, see pic. ( was purchased as usual with seller saying it was all working OK 🤬) 

Anyway it’s a well put together pistol and did function correctly but obviously will now need to put a seal in it. The mag is fine and gas tight and good quality with metal feed lips & follower etc. 

price is £40 all in posted so a cheap project or replica for someone.