Icy moons in the outer Solar System contain rocky, chondritic interiors, but this material is rarely studied under confining pressure. The contribution of rocky interiors to deformation and heat generation is therefore poorly constrained. We deformed LL6 chondrites at confining pressures ≤ 100 MPa and quasistatic strain rates, and recorded acoustic emissions (AEs) using ultrasound probes. We defined a failure envelope, measured ultrasonic velocities, and retrieved elastic moduli for the experimental conditions. Chondritic material stiffened with increasing confining pressure, and reached its peak strength at 50 MPa confining pressure. Microcracking events occurred at low stresses, during nominally “elastic” deformation, indicating that dissipative processes are possible in rocky interiors. These events were most energetic at lower differential stresses, and occurred more frequently at lower confining pressures. We suggest that chondritic interiors of icy moons are therefore stronger, less compliant, and less dissipative with increasing pressure and size.