On the physics of momentum in ballistics: Can the human body be displaced or knocked down by a small arms projectile?
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Shooting incidents are often portrayed as resulting in a sometimes violent backwards displacement of the victim. This opinion is also not infrequently held by expert witnesses. The physical force responsible for this would be momentum (mass x velocity). The physics of momentum in ballistic injury is explained in detail. The maximum momentum transferred from different small arms projectiles including large calibre rifles and a 12-gauge shotgun only results in a backwards motion of a 80 kg target body of 0.01–0.18 m/s, which is negligible compared to the velocity of a pedestrian (1–2 m/s). Furthermore, counterbalance is constantly maintained by neurophysiological reflexes. So the effect of the momentum transferred from the missile is virtually zero and there is no backwards motion of the person shot. Empirical evidence verifying these calculations can be obtained from hunting big game, from human gunshot victims and from a video documentary demonstrating the lack of any backwards motion of a person wearing body armour after hits from a centre fire rifle. So the alleged backwards hurling of a person shot is nothing but a myth which should be refuted not only because it is incorrect but also because it can result in miscarriages of justice.
Key wordsGunshot wounds Momentum Physics Wound ballistics
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- Fackler ML (1992) Police handgun ammunition selection. Wound Ballistics Rev 1(3):32–37Google Scholar
- Gonzales TA, Vance M, Helpern M, Umberger CJ (1954) Legal medicine. Pathology and toxicology, 2nd edn. Appleton-Century Crofts, New York, pp 381–453Google Scholar
- Jason A (1987) Deadly effects: wound ballistics. Video documentary, ANITE productions, Pinole, CAGoogle Scholar
- Knight B (1991) Forensic pathology. Edward Arnold, London, pp 222–251Google Scholar
- Sellier K, Kneubuehl BP (1994) Wound ballistics and the scientific background. Elsevier, Amsterdam New YorkGoogle Scholar
- Smith S, Fiddes FS (1955) Forensic medicine. 10th edn. Churchill, London, pp 173–200Google Scholar
- Tedeschi CG, Eckert WG, Tedeschi LG (1977) Forensic medicine, vol. 1 Mechanical Trauma. Saunders, Philadelphia, pp 510–526Google Scholar