Initial Measurement Results for 20 NIST RM 8240 Standard Bullets
Li Ma, Jun-Feng Song, Eric P. Whitenton, Theodore V. Vorburger, J Zhou, A Zheng
The SRM (Standard Reference Material) 2460 standard bullets are developed at the National Institute of Standards and Technology (NIST) to support the National Integrated Ballistics Information Network (NIBIN), recently established by the Bureau of Alcohol, Tobacco and Firearms (ATF) and the Federal Bureau of Investigation (FBI). The SRM 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 at ATF and FBI using six different guns. By using the virtual signature standard to control the tool path on a numerically controlled diamond turning machine at NIST, 40 SRM bullets were produced. A bullet signature measurement system based on a stylus instrument was developed at NIST. A comparison parameter and an algorithm using auto- and cross-correlation functions were proposed for qualifying the bullet signature differences between the SRM bullets and the virtual bullet signature standard. When two compared signatures are exactly the same (point by point), their cross-correlation function (CCF) value will be equal to 100%. In this paper, initial measurement results for 40 SRM standard bullets, each measured at six land impressions, are summarized. The measurement results show that the CCF values for the 240 signature measurements are higher than 95%, with most of them even higher than 99 %. These results demonstrate the high reproducibility for both the manufacturing process and the measurement system for the NIST SRM 2460 standard bullets.
, Song, J.
, Whitenton, E.
, Vorburger, T.
, Zhou, J.
and Zheng, A.
Initial Measurement Results for 20 NIST RM 8240 Standard Bullets, Proceedings of Measurement Science Conference, Los Angeles, CA
(Accessed December 5, 2023)