Hydraulic recoil mechanism
Encyclopedia
A Hydraulic recoil mechanism is a way of hindering recoil
and adding to the accuracy and fire power of the artillery piece.
Recoil
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gasses, according to Newton's third law...
and adding to the accuracy and fire power of the artillery piece.