RICOCHET

Explanation about ricochet phenomenon in external ballistics

1. RICOCHET FORENSIC BALLISTICS Submitted By:- Shivam Gupta(5 th S em ) Submitted To:- Mr. Ketan Sir SVVV, Indore

2. What is ricochet? Ricochet is a phenomenon refers to the deflection of projectile from its trajectory or line of motion after hitting a hard object even from bones.

3. Variables Ricochets occur when a bullet or bullet fragment is deflected by an object rather than penetrating and becoming embedded in that object. Ricochet behaviour may vary with bullet shape, bullet material, spin, velocity (and distance), target material and the angle of incidence .

4. Velocity High-velocity rifle cartridges have higher probability of bullet penetration, because increased energy released by an identical bullet may fracture or temporarily melt the target at the point of impact.

5. Bullet Sectional density, or mass of the bullet divided by the frontal area of the bullet, increases penetration of resistant surfaces. Elongated, spin-stabilized bullets fired from rifled firearms have greater sectional density than spherical bullets of the same diameter made from the same material; and elongated rifle cartridge bullets have greater sectional density than short bullets of the same diameter handgun cartridges.

6. Target Material Comparative hardness and density determine the results of collisions with bullets. Bullets tend to penetrate low density materials like air with little deflection, although friction causes rotated projectiles to drift in the direction of rifling twist as the bullet falls through the atmosphere under the influence of gravity. 

7. Angle The angle of departure, both vertically and horizontally, is difficult to calculate or predict due to the many variables involved, not the least of which is the deformation of the bullet caused by its impact with the surface it strikes. Probability of ricochet is highest from surfaces approximately parallel to the axis of bullet movement, and grazing ricochets typically depart the surface at a smaller angle than the angle of incidence (or approach).

8. Consequences Not all ricochets are accidental. Some bullets are fired to intentionally ricochet, just as in ricochets of some ball games like basketball and pool.  The problem with unintentional ricochets is potential damage caused to objects outside the intended path of the bullet . Damage potential of ricochets, like bullets, is proportional to the  mass of the bullet fragment and the  square of its velocity . Ricochets can be lethal. A notable death caused by ricochet was the hostage Katrina Dawson during the  Lindt cafe siege in December 2014, killed by a ricochet from a police bullet when tactical officers stormed the building .

9. When Bullet Deflects It Causes Following Effects :- The trajectory of bullet effectively gets changed. Apart from the fact of changing direction of motion of the projectile the angle of deflection also undergoes a substantial change. After ricochet the projectile tends to lose considerable amount of its energy which may be anything up to one third of its total energy. It loses gyroscopic stability and may tumble after ricocheting. The range will decrease which is in contrary to the popular belief that a ricocheting bullet will have the elevation for maximum range. The projectile may carry some material from the surface of the target after ricochet.

10. Critical Angle & Ricochet Angle: The actual degree at a bullet producing ricochet from a surface is called the Ricochet Angle and the minimum angle at which the bullet may produce Ricochet phenomenon is known as the Critical Angle.

11. Wounds & Ricocheting Wounds produced by bullets ricocheting from hard surfaces can be easily identified. The entry hole caused by a bullet after ricocheting will be very distinctive as it is caused by a distorted bullet which will generally have ragged edges. After it enters the body, the bullet due to its inherent unstable condition, tumble end over end and would leave a large and irregular channel. Jacketed bullets tends to break up on ricocheting and possibility of recovery of fragmented jacket and lead core are more.

12. Fatal wounds & Ricocheting: Ricocheting of bullets cause serious injuries even fatal ones. It is well established that after ricochet the bullet substantially gets deformed in case of lead or gets fragmented in case of jacket. The ragged shape of bullet then is capable enough to produce devastating effect and the entry wound may be fatal. “Billiard Ball phenomenon” and “Dum Dum Bullets” are good examples for producing fatal injuries.

13. Case related to Fatal injuries & Ricocheting: A notable example of the power of a ricochet was given by the fatal accident which occurred in the fall of 1933, when an actor Russ Columbo was accidently killed by the explosion of the charge in an old muzzle-loading pistol which was being kept as a curio. According to Newspaper accounts, a friend of the actor snapped the head of a match on the nipple of the gun, which was thought to be unloaded, and it went off and the bullet struck a piece of furniture and then bounced and struck the actor causing so serious injuries that it resulted in his death.

14. Thank You