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#1
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02-22-2014, 01:51 PM
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Firearm Injuries - A Brief Overview
Autoloading, semi-automatic pistol. The force generated from each bullet fired causes a new round to be chambered from the magazine The detachable magazine that holds 17 rounds is placed into the grip Six round revolver Semi-automatic rifle. A rifle is a firearm with a long barrel, which gives the larger rounds more accuracy and range. The energy of the fired bullets is enormous. The .308 caliber copper jacketed bullets fired by this rifle can blow a hole in plate steel 1/4" thick The appearances of the most common handgun and rifle rounds are shown here. In general, it is difficult to tell from the wound exactly what round was used When bullets strike a target, there can be considerable deformation and fragmentation. In this case, the lead bullet has become markedly deformed and has separated from the copper jacket at the right Bullets fired from a gun will have "striae" (linear grooves) imparted as a consequence of traversing the barrel, and these marks help to identify the weapon. Comparison of bullets involves "class" (caliber and rifling) and "individual" characteristics based upon burrs or imperfections in the barrel, particularly the muzzle, that impart specific markings, or striae, to fired bullets. Individual characteristics are used to try and determine if a specific gun was used in a crime. The sets of bullets shown here are from the same class, but deformations in recovered bullets (the right of each pair) can complicate comparison Much of the damage done by a bullet results from the tumbling motion and the cavitation in the tissue. This is the bullet track in clay from a .38 caliber round, demonstrating that the wound track is much larger than .38 inches Contact gunshot entrance wound. Since the barrel contacts the skin, the gases released by the fired round go into the subcutaneous tissue and cause the star-shaped laceration. Note also the grey-black discoloration from the soot, as well as the faint abrasion ring An abrasion ring, formed when the force of the gases entering below the skin blows the skin surface back against the muzzle of the gun, is seen here in this contact range gunshot wound to the right temple Abrasion ring and a very clear muzzle imprint, are seen in this contact range gunshot wound This is a contact range gunshot entrance wound with grey-black discoloration from the burned powder The diagram above illustrates the basic differences between the skin appearance of a close-range contact wound and distant range wound. The appearance of the wounding characteristics in the skull is shown in the lower diagram in which there is bevelling of the skull outward away from the direction of origin of the bullet The surface of the skull demonstrates the heavy soot in this contact range entrance wound, as well as radiating fracture lines Histologic examination of the entrance wound site on the skin shows black gunshot residue and coagulative necrosis This is an intermediate range gunshot entrance wound in which there is powder "tattooing" around the entrance site Powder tattooing is seen in this intermediate range gunshot wound. The actual entrance site is somewhat irregular, because the bullet can tumble in flight Displayed here is an entrance at the left and an exit at the right. This particular bullet struck at an angle to produce the ovoid entrance. Exit wounds vary considerably in size and shape because the bullet can be deformed in its transit through the body. There may be no exit wound at all if the bullet's energy is absorbed by the tissues. Some bullets are designed to deform so that all their energy will be converted to tissue damage and not exit Here is a slit-like exit wound. The projectile becamed deformed and flattened while traversing the body, producing a laceration upon exit. Note that there is no powder or soot visible in this exit wound |
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#5
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02-22-2014, 03:57 PM
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| My Rank: CORPORAL Poster Rank:1438 Join Date: Apr 2012 Posts: 404 Mentioned: 1 Post(s) Quoted: 151 Post(s)
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Re: Firearm Injuries - A Brief Overview
I studied those same pics in med school. Utah state I think has some good ones too. Nice.
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