This paper creates a fuse-projectile-barrel coupling model and conducts an implicit-explicit sequential finite element dynamic simulation to analyze the response of the components in ammunition to shock loadings during the whole launch process accurately. The engraving process continues at 3.05 ms and leads to the acceleration fluctuation of the fuse bearings. The deflection of the gun barrel due to gravity at 52 degrees quadrant elevation (QE) is acquired. Then the displacement and velocity of the projectile are obtained to verify the gun tube deflection. The bearing axial and radial acceleration in the fuse are depicted. The results indicate that the axial acceleration imposed on the bearings during launch is a major loading, and base pressure and pressure dissipation result in shock loadings on the bearings. The accelerated spin and collision of the projectile with the barrel produce centrifugal inertia force and gyroscopic coupling, which influence the radial acceleration. In addition to this, a calculation method is proposed to work out the maximal contact stress of the bearing's components. The method is combined with the bearings' components maximal acceleration from simulation. The results of the research prove that the calculation method is correct and credible. The research conclusions provide some reference for the structural design of a trajectory correcting fuse.