We apply a hydrodynamic approach to analyze ejecta emanating from doubly shocked liquid metals. In particular, we are interested in characterizing ejecta velocities in such situations by treating the problem as a limiting case of the Richtmyer–Meshkov instability. We find existing models for ejecta velocities do not adequately capture all the relevant physics, including compressibility, nonlinearities, and nonstandard shapes. We propose an empirical model that is capable of describing ejecta behavior across the entire parameter range of interest. We then suggest a protocol to apply this model when the donor material is shocked twice in rapid succession. Finally, the model and the suggested approach are validated using detailed continuum hydrodynamic simulations. The results provide a baseline understanding of the hydrodynamic aspects of ejecta, which can then be used to interpret experimental data from target experiments.