The interaction between clothing and air weapon pellets

Abstract

Comparatively few studies have been carried out on air weapon injuries yet there are significant number of injuries and fatalities caused by these low power weapons because of their availability and the public perception that because they need no licence they are assumed to be safe. In this study ballistic gel was tested by Bloom and rupture tests to check on consistency of production. Two series of tests were carried out firing into unclothed gel blocks and blocks loosely covered by different items of clothing to simulate attire (tee shirt, jeans, fleece, and jacket). The damage to the clothing caused by different shaped pellets when fired at different ranges was examined. The apparent hole size was affected by the shape of pellet (round, pointed, flat and hollow point) and whether damage was predominantly caused by pushing yarn to one side or by laceration of the yarn through cutting or tearing. The study also compared penetration into clothed gel and unclothed gel under identical conditions, and loose clothing greatly reduced penetration. With loose clothing at 9.1 m range clothing reduced penetration to 50-70% of the penetration of unclothed gel but at 18.3m range only 7 out of 36 shots penetrated the gel. This cannot be accounted for by the energy loss at the longer range (3-7% reduction from 9.1 m to 18.3 m range in unclothed gels) and it is suggested that impulse may have a role to play. Shots that did not penetrate the gel were used to estimate the possible stopping time for the pellet (around 75 μs) and force (1700 N) or stress (100 MPa) required to bring the pellet to a halt. Even with these low energy projectiles, cloth fibres were entrained in the gel showing the potential for penetration of the body and subsequent infection.

A comparison of penetration and damage caused by different types of arrowheads on loose and tight fit clothing

“…The observation of loose fit clothing reducing the penetration capacity was similar to the results observed during the Wightman, Wark and Thomson [18] study with air rifle pellets.…”

“…Several studies have been carried out with regards to penetration capacity in firearms, air weapons and even bladed weapons. The Wightman, Wark and Thomson [18] study found that clothing that was in contact with the gelatine provided a reduced penetration capacity of various types of air rifle pellets, however, a greater relative standard deviation was found when the clothing was loosely wrapped around the gelatine. In the same study, it was also noted that any damage caused to clothing was dependent on the pellet shape, with the pointed pellets causing the least damage and the domed pellets causing the most damage.…”

The effect of military clothing on gunshot wounding patterns in gelatine

“…More recently published was a study that showed the presence of a layer of denim on a model of a deer femur embedded in 20% (by mass) gelatine led to an increase in the risk of indirect femoral fracture when shot by 5.56 NATO ammunition [ 22 ], followed by an increasing interest in examining clothing effects on wounding in ballistic research [e.g. 4 , 20 , 21 , 23 , 44 , 45 ]. Published research has demonstrated that intermediate layers (clothing or other personal protective equipment) can affect damage sustained by a gelatine block during ballistic testing [e.g.…”

Preliminary investigation into the use of Micro-CT scanning on impact damage to fabric, tissue and bone caused by both round and flat nosed bullets

“…The majority of ballistic research tends to focus on the difference between the calibre rather than the difference between bullets. Wightman, Beard and Allison [17] looked into the difference between types of air rifle pellets and how they interacted with bone, then in 2015, Wightman, Wark and Thomson [18], investigated the interaction between air rifle pellets and clothing. This study aims to combine these two studies and determine the impact damage to bone by both round and flat nosed bullets and whether the introduction of fabrics, as well as a skin substitute, will have any effect on the penetration depth.…”