Announcement

Collapse
No announcement yet.

Wound ballistics

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Having been involuntarily recruited as a subject in human trials, I can state conclusively that a large caliber handgun and a 12 gauge shotgun pressed against the human skull sends fear waves through that body that cause the spontaneous release of urine and focuses one on the immediate present.

    Working in an ER and growing up in the hood, I learned that bullets and pellets sure make a mess out of human flesh.

    I leave the heavier scientific findings to y'all.
    Last edited by Foolish Old; 08-20-2007, 04:11 PM.
    Foolish

    "We have met the enemy and he is us."-POGO.

    "I have great faith in fools; self-confidence my friends call it."~Edgar Allan Poe

    "Dream big, you might never wake up!"- Snoop Dogg

    Comment


    • #17
      Originally posted by Tiger Racing
      The terms "shock" and "sonic" are being used interchangeably in this thread. Do "sonic wave" and "shock wave" truly refer to the same phenomena?

      C.
      Yeah, two different things. I'll watch myself.

      Comment


      • #18
        Originally posted by Foolish Old
        Having been involuntarily recruited as a subject in human trials, I can state conclusively that a large caliber handgun and a 12 gauge shotgun pressed against the human skull sends fear waves through that body that cause the spontaneous release of urine and focuses one on the immediate present.
        I've had a couple pointed but never pressed up against me. It would be frightening.

        Comment


        • #19
          Originally posted by NorthQuad
          I've had a couple pointed but never pressed up against me. It would be frightening.
          It is. Especially when the gun holders are bug-eyed with fear themselves.
          Foolish

          "We have met the enemy and he is us."-POGO.

          "I have great faith in fools; self-confidence my friends call it."~Edgar Allan Poe

          "Dream big, you might never wake up!"- Snoop Dogg

          Comment


          • #20
            Originally posted by Hype62
            I find this article interesting, because my sci was due to a bullet injury. Was at the wrong place at the wrong time. God I hate guns.
            I am just curious, did you hate guns before you were injured? I was injured on a motorcycle and wish I could ride one today. As for guns I dont leave home without one with the world like it is today. Being a quad walking with a cane I feel I am an easy mark for any asshole, and there are plenty around.

            Comment


            • #21
              Let me try to define the two phenomena of sonic wave versus temporary cavity. In an article entitled

              Gunshot Wounds: 1. Bullets, Ballistics, and Mechanisms of Injury
              Jeremy J. Hollerman,1 Martin L. Fackler,2 Douglas M. CoIdwelI,3 and Yoram Ben-Menachem4

              the authors, pointd out that bullets wound tissues in two ways:
              Two major mechanisms of wounding occur: the crushing
              of the tissue struck by the projectile (forming the permanent
              cavity), and the radial stretching of the projectile path walls
              (forming a temporary cavity) (Fig. 1).
              In addition, a sonic pressure wave precedes the projectile
              through tissue. The sonic pressure wave plays no part in
              wounding. In air, the speed of sound is approximately 300 m/
              sec; in soft tissue, it is approximately 1 500 rn/sec. When a
              bullet enters soft tissue, the sonic pressure wave forms a
              hemispherical arc ahead of the advancing bullet. The shortlived
              sonic pressure pulse created may reach pressures of up
              to 100 atm (1.01 x 1 Oı Pa). The duration of this pulse is
              approximately 2 ısec [4]. Research reported in 1947 [5]
              determined that this sonic shock wave has no damaging
              effect on tissue, a finding since confirmed by clinical experience
              with sonic pressure wave lithotripsy, in which tissue
              receives sonic pressure waves two to three times greater
              than that produced by a supersonic rifle bullet [6]. The sonic
              pressure wave must not be confused with the temporary
              cavity, which is discussed later.
              There is a great deal of misunderstanding of the term sonic wave. It does not contribute to the wounding. Yet, you see this over and over again in many articles. Here is another article from the Journal of Trauma,
              http://www.neurosurgery.org/sections...ethodology.pdf -
              INFLUENCE OF BALLISTICS ON PBI
              Ballistics is the study of the dynamics of projectiles;
              wound ballistics is the study of the projectile’s action in
              tissue. Penetrating head wounds generally result from bullets,
              shrapnel, and lower velocity sharp objects, such as arrows
              and knives. The ability to penetrate the intracranial space is
              determined by the energy and shape of the object, the angle
              of approach, and the characteristics of intervening tissues
              (skull, muscle, mucosa, etc.). The primary injury to the brain
              is related to the ballistic properties (kinetic energy, mass,
              velocity, shape, etc.) of the projectile and any secondary
              projectiles, such as bone or metallic fragments.
              Lower velocity sharp projectiles, such as arrows (120–
              250 ft/s [36–76 m/s]), wooden sticks, knives, and pencils
              create a track of primary tissue damage without substantial
              bruising or blunt tearing of surrounding tissue. In contrast,
              higher velocity projectiles result in a more complex wounding
              pattern. An impact shock wave precedes the projectile.
              This sonic wave is very brief (2 s) and does not contributee
              substantially to tissue destruction. As the projectile penetrates
              brain tissue, it crushes tissue in its path, creating a permanent
              track of tissue injury. Higher velocity projectiles will impart
              an additional temporary cavitation effect in their wake, which
              is a velocity-related phenomenon. This results from the transmission
              of the kinetic energy of the projectile to the surrounding
              tissue, thus rapidly compressing it tangentially from the
              primary track. After the cavity expands to its maximum size,
              it starts to collapse under negative pressure and can suck in
              external debris. This cavity will then often undergo smaller
              expansions and contractions of diminishing amplitude. In
              relatively inelastic tissue, such as the brain, this results in a
              track of injury often 10 to 20 times the size of the offending
              projectile.

              The size of this temporary cavity is related to the velocity,
              mass, and shape of the projectile. The velocity and mass
              are proportional to the kinetic energy as defined by the
              equation KE  1/2 mv2. The shape of the projectile influences
              its velocity. Every projectile has a ballistic coefficient
              that expresses its ability to overcome air resistance and thus
              maintain velocity. A form factor in the equation for the
              ballistic coefficient relates to the shape. The sharper the nose
              of a bullet, the less the velocity will be decreased by air
              resistance. The rounder the nose of a bullet or more irregular
              the shape (as in shrapnel), the quicker the velocity slows and
              kinetic energy decreases. Projectiles traveling at higher velocities
              carry more kinetic energy and will create larger temporary
              cavities.

              The shape of the projectile also affects the size of the
              temporary cavity through its influence on yaw. Yaw describes
              the rotation of a projectile around its long axis. Although
              small amounts of circular motion (precession and
              nutation) occur during flight, projectiles will often tumble
              when striking tissue. As the projectile rotates 90 degrees to its
              long axis, the primary track of tissue destruction increases.
              The entire length of a projectile contributes to this permanent
              track when the yaw is maximized at 90 degrees. This imparts
              more kinetic energy to the tissue, and the size of the temporary
              cavity increases. This also explains why the exit wound
              is generally larger than the entrance wound in perforating
              injuries. For these reasons, a .45 automatic pistol (muzzle
              velocity of 869 ft/s [265 m/s] and a short round-nosed projectile
              with little yaw) will create a very small temporary
              cavity. Conversely, a 7.62-mm rifle (muzzle velocity 2,830
              ft/s [863 m/s] and a long, sharp nose with maximum yaw)
              will create a very large temporary cavity.

              The caliber of a weapon is defined as the internal diameter
              of the barrel and thus represents the widest diameter of
              the bullet. This may be expressed in millimeters, as in a 9-mm
              handgun, or in inches, as in a .44 magnum. Magnum refers to
              a load with extra powder, thereby imparting more velocity to
              the projectile. In general, handguns (710–1,610 ft/s [216–
              491 m/s]) will be lower velocity weapons than rifles (2,690–
              3,150 ft/s [820–960 m/s]). The velocity also will be degraded
              over distance secondary to the ballistic coefficient discussed
              above. For example, the U.S. military M16A1 rifle has a
              muzzle velocity of 3,150 ft/s (960 m/s), which drops to 2,186
              ft/s (666 m/s) at 300 yards (274 m) and 835 ft/s (255 m/s) at
              1,000 yards (914 m).

              One projectile characteristic deserving mention is fragmentation
              potential. In addition to yaw, projectiles can also
              deform or fragment on striking tissue. Copper jacketing of
              lead bullets, as mandated for military rounds by The Hague
              Peace Conference (1899), helps limit the fragmentation potential.
              Irregularities made by scoring the surface of the bullet
              (dum-dums) lead to increased fragmentation. Fragmenting
              rounds can create multiple injury tracks, as each fragment
              becomes an irregular, tumbling projectile. The Glaser round
              is filled with small pellets that disperse on impact. Hollow
              point rounds, often seen in civilian shootings, expand their
              diameter on impact, thus creating a larger primary wound
              track and more destructive temporary cavitation effects. Explosive
              bullets are designed to detonate on impact and will
              thus produce extensive tissue injury with additional kinetic
              energy transfer.

              Comment


              • #22
                Funny, being around firearms all my life I've heard about "Explosive bullets" but I've NEVER seen one nor known anyone that has either. How do you keep something that is supposed to explode when contacting soft skin from not exploding under the forces of excelleration from firing?.....I sure as hell wouldn't want to shoot one.
                "Timid men prefer the calm of despotism to the tempestuous sea of liberty." ~ Thomas Jefferson

                Comment


                • #23
                  Ok, in my head I had pictured a "sonic wave" as a fast moving wave of flesh caused from the pressure of the bullet hitting and passing through it.

                  I'm not sure what you would call this wave of flesh that's caused from the bullet passing through. But it can sure cause a lot of damage.

                  Comment


                  • #24
                    Originally posted by NorthQuad
                    Ok, in my head I had pictured a "sonic wave" as a fast moving wave of flesh caused from the pressure of the bullet hitting and passing through it.

                    I'm not sure what you would call this wave of flesh that's caused from the bullet passing through. But it can sure cause a lot of damage.
                    Maybe that's why I have nightmares about waves of flesh coming to get me. Someone make them stop, please make them stop.
                    "The world will not perish for want of wonders but for want of wonder."
                    J.B.S.Haldane

                    Comment


                    • #25
                      Originally posted by Juke_spin
                      Maybe that's why I have nightmares about waves of flesh coming to get me. Someone make them stop, please make them stop.
                      A flesh tsunami? . Oy.

                      Wise.

                      Comment


                      • #26
                        Originally posted by Wise Young
                        A flesh tsunami? . Oy.

                        Wise.
                        LOL. That would work.

                        It took me a while to figure out what was meant by "sonic wave" yesterday. Sonic wave as in the wave caused by an object breaking the sound barrier type of wave. NOT a fast ripple of flesh caused by an object passing through the body at high velocity. Which is what I had emagined it meant.

                        Comment


                        • #27
                          Originally posted by Wise Young
                          A flesh tsunami? . Oy.

                          Wise.
                          Human Flesh Tsunami


                          .

                          Comment