The measured loading and unloading particle velocity time histories in shocked metals exhibit well known deviations from typical elastic-plastic response models that are often used to describe shockwave behavior in metals. For example, shock and release wave measurements in polycrystalline metals demonstrate significant departure from the ideal elastic-plastic response upon release in particular, that shows a gradual transition from elastic behavior to fully plastic behavior, an indication that some amount of plastic deformation is occurring along the entire release path as the material unloads. It has been hypothesized that dislocations pile up at grain boundaries during the loading process creating a back-stress. As the material unloads, the dislocations reverse motion, giving rise to the observed quasielastic unloading response. The use of polycrystalline metal simplifies the experiment but complicates theoretical analysis due to the random orientations of slip planes and Burgers vectors, which are required to define the kinematics of crystal plasticity. The “averaging” that occurs in polycrystalline metals gives the perception that the plastic response is isotropic. However, single crystals are strongly anisotropic in their plasticity. We will present particle velocity time histories obtained during plane wave experiments on individual crystals of β-Sn impacted along varying orientations and varying thicknesses. Our experiments show orientation-dependence to the HEL and plastic flow.