Phenomena Associated with the Flight of Ultra-Speed Pellets. Part I. Ballistics

Abstract

Small metallic pellets have been fired at velocities up to 6 km/sec by means of modified shaped charges. Previous work in this field has been confined largely to observations of meteors and conventional shaped charges. Data obtained on ballistic phenomena verify the conventional drag force determinations extrapolated to large Mach numbers. Steel pellets at velocities of 2.5 km/sec lose little mass in flight. Pellets composed of lighter metals, such as aluminum at a velocity of 5 km/sec, burn vigorously with the emission of much light and heat. It has been found that the motion of both nonburning and burning pellets can be represented within experimental error by the empirical equation v=v 0 e −αs ,where v 0 is the initial velocity of the pellet, v is its velocity after it has traveled a distance s through the air, and α is a constant.