Hatsan MOD 125 Piston – Replacement Seal from Custom Air Seals


Purchased the piston seal replacement for the Hatsan MOD 125th from Custom Airseals out of Australia after first replacing the the breech seal.  According to the email I received from Custom Air Seals the piston seal was supposed to measure 29.20mm +/- .5 .  See results below:

  • Hatsan Stock Piston Seal: 28.65 
  • Custom Airseal Claimed (smallest): 29.2 -.5 = 28.7
  • Custom Airseals Actual: 27.87

Result: Zero compression to push the pellet out of the gun. 


Maybe look at the Air Venturi  Piston Seals.

Author: Bryon Gaskin

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