Citation

Lyall A, Carr DJ, Lankester C, Malbon C. J. R. Army Med. Corps 2016; 163(1): 35-38.

Affiliation

Mechanical Engineering, Material Science and Civil Engineering, Centre for Applied Science and Technology, Home Office Science, St Albans, Hertfordshire, UK.

Copyright

(Copyright © 2016, UK Royal Army Medical Corps)

DOI

10.1136/jramc-2015-000575

PMID

26937022

Abstract

INTRODUCTION: Some military specialists wear body armour that is more similar to police armour and provides protection from ammunition fired from pistols. During ballistic testing, these armours are mounted on a standardised type of modelling clay and the back face signature (BFS; depth of depression) formed as a result of the non-perforating impact event on to the armour is measured. This study investigated the effect of impact angle on the BFS and on the deformation of the bullet.

METHODS: Two commonly worn types of armour (HG1/A+KR1 and HG1+KR1) were considered that provide protection from pistol ammunition and sharp weapons. Armours were tested against two types of pistol ammunition (9 mm full metal jacket and 9 mm hollow point) at eight different impact angles (0°, 15°, 30°, 45°, 60°, 70°, 75° and 80°).

RESULTS: Increased impact angles resulted in smaller BFSs. Impact angle also affected whether bullets were retained in the armour; as the impact angle increased, the probability of a round exiting the side of the armour increased. Bullet deformation was affected by impact angle.

CONCLUSIONS: Understanding the deformation of bullets may assist with recreating a shooting incident and interpreting forensic evidence.

Language: en