Evaluating Measurement Uncertainty for Firearm Barrel and Overall Length Measurements

Published

November 1, 2021

Author(s)

Michael Stocker, Theodore V. Vorburger, Thomas Renegar, Robert Thompson, Mark Williford

Abstract

In recent years, more forensic laboratories are seeking accreditation to ISO 17020 and 17025. In the field of firearm and toolmark forensics, the barrel length and overall length of a firearm are typical measurements performed in the laboratory to determine if a given firearm meets legal specifications defined in criminal law. An important and sometimes challenging aspect of seeking 17025 accreditation is generating statements of measurement traceability and measurement uncertainty. In this paper, we provide a case study demonstrating how measurement traceability and measurement uncertainty are derived for firearm barrel and overall length for the purposes of meeting accreditation criteria. Data and procedures from this successfully accredited forensic laboratory will be shown.

Citation

Journal of the Association of Firearms and Toolmarks Examiners

Volume

53

Issue

4

Pub Type

Journals

Download Paper

Local Download

Keywords

barrel length, overall length, measurement uncertainty, measurement traceability, laboratory accreditation, ISO 17025

Citation

Stocker, M. , Vorburger, T. , Renegar, T. , Thompson, R. and Williford, M. (2021), Evaluating Measurement Uncertainty for Firearm Barrel and Overall Length Measurements, Journal of the Association of Firearms and Toolmarks Examiners, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929032 (Accessed October 9, 2025)