Ricochet Analysis Introduction

When a bullet strikes any surface, there is a critical angle at which the bullet will bounce off or ricochet from the surface rather than penetrate. After ricocheting from the surface, the missile will lose a considerable amount of its velocity (anything up to 35% in test firings) and, invariably, lose its stability. This is contrary to the popular belief that a ricocheting bullet will carry further than one fired at the elevation for maximum range.

The actual degree at which a bullet will ricochet from a surface is called the critical angle. Predicting this critical angle for any bullet/surface configuration is, however, extremely difficult. Factors such as bullet shape, construction, velocity and ricocheting surface all have a pronounced effect on the outcome (Figure 4.31).

Projectile Ricochet

A case illustrating how variable this can be involved the shooting at a taxi in central London by a terrorist group. The weapon involved was a 0.357" Magnum revolver which was loaded with semi-jacketed bullets, some of which had a hollow point and others which had a solid round nose.

The front windscreen of a British taxi is only angled back by approximately 15 ° and under normal circumstances, such a low angle would not be expected to support a bullet ricochet.

The first round fired at the front windscreen had a hollow-point bullet which cleanly ricocheted from the screen leaving a stripe of lead up the glass. This bullet was located at a later stage and was found to have a mirror-like flat surface on the lead portion of the nose. The second bullet fired was a round-nosed fully jacketed bullet which cleanly penetrated the glass narrowly missing the driver.

In this instance, the angle of the screen was clearly insufficient to support a ricochet with a round- nosed bullet. The hollow- point nose did, however, collapse on impact, effectively increasing the angle and allowing the bullet to ricochet from the glass.

Considering the number of times in the investigation of armed crime that incidents of ricocheting bullets are encountered, it is surprising how little literature there is on the subject. Probably the most authoritative work was by Lucien Haag (1975). Several other papers (Jauhari and Mohan, 1969; McConnell, Triplett and Rowe, 1981; Hartline, Abraham and Rowe, 1982; Rathman, 1987) have also investigated the effects of shotgun pellets ricocheting from steel and concrete.

The parameters affecting the potential to ricochet are so diverse, however, that it is difficult to lay down any firm and fast rules as to ricochet potential. Empirical studies should, therefore, be carried out for each individual case.

There are, however, a few generalizations which can be applied.

1. In most cases of bullets ricocheting from a hard surface, the angle of ricochet is considerably less than the angle of incidence (Tables 4.3 and 4.4).

As can be seen from the following tables, with hard-jacketed, high-velocity missiles striking a frangible material such as stone or concrete, it is not always the case that the angle of ricochet is less than the angle of incidence.

Table 4.3 Ricochet angles vs. incident angle for various bullets on smooth concrete.

Ricochet angle at incident angle of

Ricochet angle at incident angle of

Table 4.3 Ricochet angles vs. incident angle for various bullets on smooth concrete.

Calibre

Bullet type

Velocity (ft/s)

10 °

30 °

0.22" LR

RN

1100

1.33

1.88

0.22" LR

HP

1100

1.3

1.19

0.38" Spl

RN

650

1.02

1.5

0.357" Mag

SJHP

850

1.3

1.7

7.62 x 25 mm

FMJ

1300

2.0*

12-35*

7.62 x 39 mm

FMJ

2700

3.5*

2-25*

* Indicates severe cratering leading to variable results and, in some cases, disintegration of

bullet.

Table 4.4 Ricochet angle for 0.45 ACP FMJ bullet from various surfaces at various

incident angles.

Ricochet angle at incident angle of

Material

Calibre

15 °

2 5 °

Glass

0.45 ACP

Broke glass

Broke glass

Concrete

0.45 ACP

2"

3 °

Steel plate

0.45 ACP

2.5 °

4 °

Wood

0.45 ACP

17 °

17"

Sand

0.45 ACP

Penetrate

Penetrate

It would appear that if sufficient cratering of the surface occurs on bullet impact, the exit plane of the crater will be of greater angle than the incidence angle. This equates to the bullet striking the surface at a greater incidence angle and therefore a greater ricochet angle.

2. The critical angle for a soft or hollow-point bullet is lower than that for an equivalent fully jacketed bullet. In this instance, it would appear that the collapsing hollow-point bullet nose increases the incidence angle, thus increasing the propensity for ricochet.

3. The critical angle for a given bullet type/target medium is not velocity dependent. This effect is illustrated by Table 4.5.

4. Bullets will invariably lose their gyroscopic stability and tumble after ricocheting. This tumbling gives rise to a distinctive whine or whirring noise as the tumbling bullet passes through the air.

5. Bullets which have ricocheted from glass, steel, concrete or wood have a very distinctive flat spot which is characteristic of the material where the contact has been made. This contact point will often have paint, wood fibres or

Table 4.5 Critical angle vs. velocity for various calibres fired at water.

Calibre

Velocity (RN bullet) (ft/s)

Critical angle (degree)

0.22"

850

8

0.22"

1000

8

0.22"

1250

8.50

0.38" Spl

650

8 °

0.38" Spl

800

8 °

0.357" Mag

900

8 °

0.357 Mag

1050

8 °

NB. Some of the bullets used in this test were hollow-point. The nose was, however, filled with epoxy resin and shaped to give the desired round-nosed profile.

NB. Some of the bullets used in this test were hollow-point. The nose was, however, filled with epoxy resin and shaped to give the desired round-nosed profile.

concrete adhering to it for easy identification. If the material was glass or polished steel, the mirror-like surface is quite distinctive.

This is not, however, the case with a bullet which has ricocheted from water. Even with hollow-point bullets, it is unlikely that it will be possible to differentiate between a bullet which has ricocheted from water and one which has not.

6. Wounds produced by bullets ricocheting from hard surfaces will generally be easy to identify due to the bullet ' s tumbling action. If the bullet does happen to strike point first, the misshapen bullet will leave a distinctive entry hole generally with ragged edges. Once it enters the body, the bullet will, due to its inherent unstable condition, tumble end over end, leaving a large irregular wound channel. Jacketed bullets tend to break up on ricocheting, peppering the skin with jacket and lead core fragments.

7. High-velocity bullets with a thin jacket, for example, 0.223" or 0.220" Swift, will invariably break up before ricocheting. This applies even to water.

It is interesting to note that when round shot was used by naval vessels, ricocheting missiles from the water were a recognized form of tactics in sea warfare. By skipping a missile across the water at hull height, it was much easier to hit an enemy ship than to try and calculate the correct elevation for the missile to strike the ship during its trajectory.

This method worked well with round shot where the angle of incidence and the angle of ricochet were approximately the same. However, modern projectiles which are spin stabilized and have an aerodynamic shape do tend to rise at a greater angle after ricocheting from water, and the technique was found to be of little use.

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Responses

  • ulrich
    Do hollowpoint bullets ricochet?
    6 years ago
  • TIM
    Do hollow point bullets ricochet?
    6 years ago
  • berengario
    What angle will bullets ricochet water?
    5 years ago
  • Gabriel
    Do bullets ricochet at 12 degrees?
    5 years ago
  • ANDREAS
    Do hollow point rounds ricochet?
    5 years ago
  • ennio
    CAN HOLLOW POINT RICHEOT?
    5 years ago
  • domenica
    Can a pellet ricochet 90 degrees?
    5 years ago
  • lorene
    Does a ricochet bullet lose its trajectory?
    5 years ago
  • karly mcintosh
    Can a bullet ricochet greater than 90 degrees?
    4 years ago
  • LIISA
    How easy would it be to figure out bullet trajectory when the bullet ricochet off multiple surfaces?
    4 years ago
  • Jens M
    What angle will most bullets richochet?
    4 years ago
  • Mandy Biermann
    What makes a bullets ricochet from surfaces?
    4 years ago
  • finn
    What type of bullet has less richocet?
    4 years ago
  • p kinnunen
    Can a bullet ricochet off of sand?
    4 years ago
  • Clark
    Can a bullet richocet of a windsheild ?
    4 years ago
  • olle
    Can a bullet ricochet out of the chamber?
    4 years ago
  • juan
    What angle will a bullet ricochet?
    3 years ago
  • JUSTIINA KAUPPINEN
    How much velocity does a bullet lose ricochet?
    3 years ago
  • jonathan
    Can a bullet ricochet off a tire?
    3 years ago
  • demsas
    How much does a bullet deaccelerate on richochet?
    2 years ago
  • saare
    Do hollow point bullets richochett?
    2 years ago
  • adelbert
    How much does a richochet reduce velocity?
    1 year ago
  • aldo
    How can pellets ricochet?
    1 year ago
  • prudenzio folliero
    Can a lead bullet richoet?
    1 year ago
  • selamawit
    What percentage of rifle bullets ricochet?
    1 year ago
  • semolina
    What is the trajectory of a bullet ricocheting off water?
    1 year ago
  • andreas
    How much velocity does a bullet lose when it riccoshey?
    10 months ago
  • luwam
    What amount of water will cause a round to ricochet?
    9 months ago
  • sebastian
    How do bullets recocet off steel plate?
    7 months ago
  • Heike Freitag
    What angle for bullet ricochet off glass?
    7 months ago
  • seppo
    Is the auto ricochet angle real?
    7 months ago
  • Sonja
    Can a ricochet leave a properly designed shooting range?
    6 months ago
  • LUCE
    How much do ricochet bullets change velocity?
    6 months ago
  • Samuel
    Do bullets ricochet off wood?
    5 months ago
  • petteri uotila
    Does a richocet cause velocity loss?
    3 months ago
  • karin
    How fast do bullets richochet?
    2 months ago

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