Store separation from aircraft remains a critical aspect of flight safety and weapon system integration, particularly in modern configurations involving internal weapon bays. Traditional quasi-steady aerodynamic approaches, based on precomputed look-up tables and weak CFD/6DoF coupling, are effective for analyzing releases of underwing stores but have proven to be inadequate for capturing the highly unsteady and nonlinear aerodynamic phenomena present in cavity flows. These flows are dominated by strong longitudinal pressure gradients, broadband noise, and tonal oscillations known as Rossiter modes, all of which can significantly influence store trajectories and potentially lead to unsafe separations. To overcome these fundamental limitations, the present work develops a tightly coupled CFD/6DoF simulation methodology capable of resolving transient aerodynamic fields and dynamic store motion simultaneously, thereby enabling accurate prediction of store trajectories within unsteady flow environments such as weapon bays.