Explanation about ricochet phenomenon in external ballistics

1. RICOCHET
FORENSIC BALLISTICS
Submitted By:- Shivam Gupta(5th Sem)
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).

9. 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.

10. 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.

11. 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.

13. 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.

14. 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.

15. 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.

16. Thank You