Date of Award

Fall 12-2020

Document Type

Thesis

Degree Name

Master of Science (MS)

Department/Program

Forensic Science

Language

English

First Advisor

Peter J. Diaczuk

Second Reader

Patrick McLaughlin

Third Advisor

Andrew Winter

Abstract

In this experiment, a method of calculating ballistic coefficients of .22LR (long rifle) caliber ammunition was developed using Doppler radar to track the pre-impact and post-impact velocities of projectiles passing through gypsum board. The method demonstrated has distinct advantages in accuracy and flexibility over conventional chronograph projectile tracking that forensic firearm experts should consider when determining the optimal method to obtain a ballistic coefficient (BC). G1 and G7 ballistic coefficients were determined for three .22LR ammunition brands with respective muzzle velocities of approximately 1050ft/s (320m/s), 1230ft/s (375m/s), and 1640ft/s (500m/s) fired from a Ruger 10/22 semi-automatic carbine using an Infinition 35.5 GHz BR-3503 Doppler radar. Short ranges from 5ft (1.52m) to 25ft (7.62m) were utilized for the collection of data needed to calculate ballistic coefficients using JBM Ballistics ballistic coefficient calculator software. Calculated ballistic coefficients were then compared to manufacturer’s estimated BC and velocity losses were recorded to indicate change in stability from perforating gypsum board. The Remington ammunition, had a calculated average BCs for G1 were 0.012±001, 0.057±0.024, and 0.038±0.003 at the 5ft(1.524m), 15ft (4.572m), and 25ft (7.62m) mark; the CCI Mini Mag ammunition had calculated G1 BCs of 0.011±0.001, 0.027±0.004, and 0.05±0.01 at 5ft (1.524m), 15ft (4.572m), and 25ft(7.62m), respectively; the CCI Stinger Varmint ammunition had average G1 BCs of .03±.004, .036±.02, and .071±.02 at 5ft (1.524m), 15ft (4.572m), and 25ft (7.62m).

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