Upon recoil of the barrel, linked by rod 1 to piston 2, fluid is forced out of cylinder 3 through raised valve 4 and channel a into air tank 5, moving floating piston 6 to the right. Valve 4 is the recoil brake. The size of the orifice through which the fluid escapes is regulated to suit the fluid pressure and the force exerted by spring 8. Maximum opening of the valve is limited by stem 9. Upon counterrecoil, air compressed in air tank 5 forces out the fluid through channel d, opened ball valve 7 and channel b into cylinder 3. At this, piston 6 moves in the reverse direction. Ball valve 7 is the counterrecoil brake.
$3770$SHP,FD$