Gas-Gun Experiments Determine Forces on Penetrators Into Geological Targets

We developed a convenient laboratory procedure to determine forces on projectiles penetrating geological targets. Gas guns were used to accelerate foundry core targets (a simulated soft sandstone) to steady velocities, and the targets subsequently impacted 20.6-mm-dia penetrators instrumented with piezoelectric accelerometers. Rigid-body acceleration data were recorded for one ogival and two conical nose shapes for impact velocities between 0.2-1.2 km/s.