Hatsan Bt65 25 cal. O rings

If you know the sizes:
https://www.mcmaster.com/
​Otherwise suggest you try :
​https://hatsanusa.com/

If you know the size we can also go to https://www.theoringstore.com/. 

 





https://m.youtube.com/watch?v=L9G4ubMrR7U









Just a few corrections. Probe seals are dash#009 is. 5.28mm x 1.78mm 

Barrel external seals are 8mm x 1.5mm 90 durometer is better than 70 especially if you remove barrel frequently for cleaning.

Barrel support oring is 15mm x 1.8mm 90 durometer is best.

Output valve nearest to hammer is 11mm x 2.5mm 

Breech seals can be 6.1mm x 1.6mm or Dash # 010 which is also the size for the foster quick disconnect socket.

https://www.globaloring.com/shop/?filter_group=o-rings



You can get all your o-rings here and for the price person charge for a kit you can equip your self for the next 20 years. Nitrile Rubber seals or viton 70 in most cases

The cylinder input valve cover oring is 25mm x 1.5mm change when it becomes loose. The pressure gauge oring is 14mm x 1.78mm.

You should purchase all the seals for the rifle. And change every year or two if not damaged. You never know when a seal may go. Make a kit and keep it when hunting or out just shooting.