Aim\ To provide the application technology for decreasing the recoil force of large caliber machine gun. Methods\ Theoretical analysis and experiment on designed prototype gun is combined to analyse the performance of the floating automatic machine. Results The displacement

recoil force and firing precision of a machine gun are attained in a running fire. Conclusion\ It can be verified to make machine gun float steadily by use of the developed hydraulic spring floating machine

remarkably reduce the recoil force and improve the firing precision.