The influence of muzzle gas on the temporary cavity

Area of Science:

• Forensic Science
• Ballistics
• Trauma Analysis

Background:

• Shot range is critical for firearm injury reconstruction.
• Muzzle gases influence injury patterns in contact and near-contact shots.
• Understanding muzzle gas effects is vital for forensic pathology.

Purpose of the Study:

• To systematically investigate the influence of muzzle gases on the temporary cavity (TC).
• To analyze how varying shot ranges affect projectile dynamics and wound characteristics.

Main Methods:

• Fired 72 shots using full metal-jacketed bullets across four calibres at distances from 10 cm to contact.
• Utilized 10% ballistic gelatine (reference cube) as target medium at 4°C.
• Recorded temporary cavity formation using high-speed video (HSV) and analyzed cross-sections with the polygon method.

Main Results:

• TC shape transitioned from tubular (10-5 cm) to pear-like at ≤3 cm, characteristic of contact shots.
• TC height increased significantly below 3 cm, with contact shots doubling TC extension.
• Muzzle gas influence became evident below 3 cm, causing additional damage in specific calibres at close ranges.

Conclusions:

• Muzzle gases substantially enlarge the temporary cavity, particularly in contact and near-contact firearm incidents.
• The study quantifies the impact of muzzle gases on temporary cavity dimensions, aiding forensic reconstruction.
• Findings highlight the importance of considering muzzle gas effects in close-range shooting investigations.