NIST Bullet Signature Measurement System for RM (Refrence Material) 8240 Standard Bullets

• NCJ Number: 206522
• Journal: Journal of Forensic Sciences Volume: 49 Issue: 4 Dated: July 2004 Pages: 649-659
• Author(s): Li Ma Ph.D.; John Song; Eric Whitenton; Alan Zheng; Theodore Vorburger Ph.D.; Jack Zhou Ph.D.
• Date Published: July 2004
• Length: 11 pages
• Publication Format: Article
• Publication Type: Test/Measurement; Report (Technical)
• Language: English
• Country: United States of America

Annotation

This paper describes the National Institute of Standards and Technology's (NIST's) RM (Reference Material) 8240 standard bullets project, discusses a new parameter and algorithm for bullet signature measurements, and describes the NIST bullet signature measurement system and some initial measurement results.

Abstract

In order to establish and maintain a nationwide ballistics information network by sharing data among ballistics laboratories, it is important to establish a measurement standard for traceability, unification, and quality control of ballistics measurement. The RM 8240 standard bullets are being developed by the NIST in collaboration with the Bureau of Alcohol, Tobacco, and Firearms (ATF). These RM bullets will be used in instrument calibration and measurement quality control, as well as for the establishment of measurement traceability to the National Laboratory Center of ATF. In 1998 two prototype standard bullets were manufactured at NIST. A new parameter and algorithm were proposed for bullet signature measurements. A traceability system was also proposed to establish the measurement traceability for bullet signature measurements nationwide. In 2002 and 2003, 40 standard bullets were manufactured at NIST. The RM bullets are designed as both a virtual and a physical bullet signature standard. The virtual standard is a set of six digitized bullet signatures originally profiled from six master bullets fired with six different guns. By using the virtual signature standard to control the tool path on a numerically controlled diamond turning machine at NIST, the 40 RM bullets were produced. Initial test results indicate that the machined bullet signatures are highly uniform among the 40 RM bullets and are in good agreement with the virtual signature standard. Measurements on 240 bullet signatures of the 40 RM 8240 standard bullets show that the cross-correlation functions (CCF) between the measured bullet signature and the virtual bullet signature standard are higher than 95 percent. These measurement results demonstrate the high reproducibility for both the bullet signature measurement system and the manufacturing process of the RM bullets. 5 tables, 12 figures, and 15 references