AFTE Store - Bullet Penetration and Perforation of Sheet Metal

Nearly a decade ago, Dr. Nennstiel of Germany’s BKA presented a substantial amount of research on the nature and behavior of bullets striking a standard thickness of sheet metal. This superlative work appeared in Volume 18, Number 2, of the AFTE Journal and should be re-read by anone interested in this subject. The present effort by this author ‘rediscovers some of Dr. Nennstiel’s findings and, in a small way, adds to his observations. The primary focus of this writer’s work was to evaluate the effects of bullet weight, bullet nose shape, and bullet hardness on penetration and perforation of sheet metal while holding caliber, metal thickness and impact angle constant. Bullet deformation and post-impact behavior was also of interest with some of the results on these topics reported herein. The substantial difference between the threshold velocity necessary for perforation vs. Velocity loss upon perforation observed by Nennstiel is reaffirmed. The fate and behavior of the ‘plug’ of metal punched out during the passage of ‘hard’ bullets through sheet metal, the damaged incurred by the perforating bullets and nature of the bullet holes were studied and are described in this article. Finally, the role of metal thickness while holding the bullet’s caliber, weight, nose shape, impact velocity and Impact angle constant is presented. All of these matters have forensic implications when studying or evaluating projectiles strikes on metal objects such as automobiles and airplanes.