NCJ Number
148189
Journal
Journal of the Forensic Science Society Volume: 34 Issue: 1 Dated: (January-March 1994) Pages: 29-35
Date Published
1994
Length
7 pages
Annotation
This study measured the energy and angular distributions of pistol bullet fragments as a function of incidence angle after they struck steel and concrete.
Abstract
The experiment captured the bullet fragments in a ballistic pendulum, which allowed measurement of the average velocity of all the fragments. The firearm was discharged from a distance of approximately 4 meters, so the bullet struck the target plate or slab at the required angle very close to the face of the pendulum. After impact, the bullet and the remaining fragments were embedded in the pendulum, causing it to move. To test the experimental technique, the muzzle velocities of the bullets were measured by firing them directly into the pendulum and comparing the results with the manufacturer's specifications. Bullets that struck concrete at angles of between 10 and 50 degrees produced fragments whose residual kinetic energy followed a linear relationship with the angle of incidence. Thus, at 45 degrees the residual energy was approximately 30 percent of the incident energy. When targets were of 6 mm sheet steel, there was no significant damage to or marking of the surface. For incidence angles of up to 30 degrees, the bullets tended to stay in one piece, carrying approximately 75 percent of their original energy. For incidence angles greater than 30 degrees, all bullets tended to fragment into many pieces. 5 figures and 2 tables