A series of light gas gun impact experiments were performed with piezoresistive ytterbium (Yb) gauges in longitudinal and lateral orientations embedded in the plastic bonded explosive PBX 9501. These experiments were performed to evaluate the feasibility of using this method to measure lateral stresses and shear strength dynamically in PBX 9501. Ytterbium was chosen as a gauge material based on its high piezoresistance changes at low stress levels. Experiments were performed at longitudinal impact stresses of approximately 0.6 GPa, which is above the yield point of Yb, near the dynamic yield point of PBX 9501, at a level that is comparable with other impact data, and relevant to several multidimensional safety tests. Results show that PBX 9501 does maintain strength throughout compression. Because of poor reproducibility observed in the experiments presented, it appears unlikely that stress extraction from these gauge results would yield an estimate of shear strength at this impact stress with acceptable error.