Wound Ballistics Of Rifled Firearm.pptx

This presentation is a brief about the wound ballistics of Rifled firearm

1. Wound Ballistics Of Rifled Firearm Submitted by:- Submitted to:- Pallavi Kumari Dept. of Forensic Sciences SHUATS

2. INTRODUCTION Forensic Ballistics:- The science of ballistic has been develop to facilitate the examination of firearms, ammunition and other related matter. It also include the study of trajectory pathway caused by the bullet. Forensic ballistic was first coined by the Colonel Calvin Goddard also known as father of Ballistic.

3. Types of ballistics Internal Ballistics :- Internal mechanism within the firearm from pulling the trigger upto bullet leaves the muzzle end. External Ballistics :- External study of bullet as soon as bullet leaves the muzzle end upto hitting the target(Trajectory pathway). Terminal Ballistics :- As soon as bullet hits the target or fall down due to gravity comes under the terminal ballistic in case of non living target.

4. Rifled Firearm

5. WOUND BALLISTICS When a projectile hits a living targets it causes some effect or creates the wound this phenomena comes under the wound ballistics. It involves following elements for proper understanding. The Firearms The Projectile The Velocity of projectile Range of fire Nature of target

6. Mechanism of injury When a projectile strikes the human body it depresses and compresses the skin, flesh and the bone underneath. The pressure continued, pressure stretches them beyond the elastic limits and a hole is created and the bullet is entered inside. The hole on the skin therefore appears, on the non-stretched skin smaller than the size of the projectile which created the wound when it was stretched . Secondly, kinetic energy transfer occurs during retardation of the bullet and this may cause damage outside the tract.

7. Factors influencing the efficiency of kinetic energy transfer Kinetic energy of a body which is proportional to mass and velocity. E = ½ mv 2 Projectile’s deformation and fragmentation. Entrance profile and path travelled through the body. Biological characteristics of the transit tissues.

8. GUNSHOT WOUND Gunshot Wound are either penetrating or perforating or both. Penetrating wound – when a bullet enters an object and does not exit. Perforating wound :- The bullet passes completely through an object. Both penetrating and perforating :- occur when a missile strikes the head and passes through the skull and brain and rest under the scalp, thus producing a penetrating wound of the head, but perforating wound of skull and brain.

9. CAVITATION A permanent cavity is formed by the path of the bullet itself. A temporary cavity is formed by continued forward acceleration of the medium (air or tissue) in the walk of the bullet causing the wound cavity to be stretched outward.

10. wound Mainly wound classify in two category Entry Wound Exit Wound Entry wound :- Direction of wound from where bullet enters into body. Exit wound :- it is point from where bullet exit or leave the body after penetration.

11. Entry wound Basically there are 4 types of entry wound are present:- Contact wound Close wound Near/ Intermediate wound Distant wound

12. Contact wound Wound is circular and smaller ( may be stellate shaped over scalp) Burning/blackening of immediate wound edges Soot within the tissues may be found (usually is less) Muzzle mark/imprint Inverted margins of the wound Local burning of skin and hair. Surrounding bruises.

13. Close wound Almost always circular in shape Edges are inverted Collar of abrasion ‘Metal fouling’ Burning effects (within a few centimeters) Tattooing around (or stippling)

14. Near wound From 30cm to 60cm Entry wound smaller than bullet size Circular in shape No blast effect Blackening and singeing are absent Tattooing may be present.

15. Distant WOUND From more than 60cm to several kilometers entry wounds appear alike There is abrasion collar around entry wound Wound is inverted Ring of dirt or grease ring A bullet striking sideways may produce a rectangular lacerated wound.

16. Exit wound Exit wound is larger in size as compare to entry wound. The margins are everted in nature. Tissue distribution is more. When bullet exit after entering into a body it may be sometimes contain different fragment along with the mass of tissues of body. Due to which the exit wound is generally larger in size.

17. Ricochet bullet A bullet when enter into the body may get deviated due to hitting with hard object like bone and may follow another path. In such circumstances the exit wound may be found at different places. This phenomena is known as ricochet bullet.

18. Terms related to wound Tattooing Blackening Scorching Abrasion collar Greece collar Burning

19. Difference between entry and exit wound Features Entry wound Exit wound Size Usually small except in contact wound Bigger than entry wound Edges Inverted Everted Burning, singing and blackening Present Absent Clothes fiber May be seen Absent Carbon monoxides Can be detected in high quantity May be present but in very less as compared to entry wound Abrasion collar Present Absent Greece or dirt collar May be present Absent

20. References Forensic Science in Crime Investigation (B S Nabar) Wikipedia. Di Maio, Vincent J. Gunshot Wounds: Practical Aspects of Firearms, Ballistics, and Forensic Techniques, Second Edition, CRC Press, New York, 1999.

21. Thank you