The concept of soft recoil mechanism is to accelerate the recoiling parts forward prior to the firing and to fire the round when the forward momentum of the recoiling parts is attained for the required level. The conventional recoil mechanism for the gun is to provide the retarding force acting on the gun so as to brake the reward motion in the firing cycle. In recent years, the concept of the soft recoil mechanism has been developed. The soft recoil mechanism is introduced for reducing the firing shock and the reaction force due to the forward momentum of the recoiling parts prior to the firing. This paper is to analyze the theory of the soft recoil mechanism and to demonstrate the feasibility for the realistic application for a large caliber gun system. To do this, the numerical simulations for the recoil dynamics and the shock response analysis have been approached.