An experimental investigation was conducted to measure the forces, moments, and pressure distributions on the generic store separating from a rectangular box cavity contained in a flat plate surface at supersonic speeds. Pressure distributions inside the cavity and oil flow and vapor-screen photographs of the cavity flow field were also obtained. The measurements were obtained for the store separating from a flat plate surface, from two shallow cavities having length to depth ratios (L/h) of 16.778 and 12.073, and from a deep cavity having L/h = 6.730. Measurements for the shallow cavities were obtained both with and without rectangular doors attached to sides of the cavities. The tests were conducted at free stream Mach numbers of 1.69, 2.00 and 2.65 for a free stream Reynolds number per foot of 2 x 10(exp 6). Presented here are a discussion of the results, a complete tabulation of the pressure data, figures of both the pressure and force and moment data, and representative oil flow and vapor screen photographs.