Behaviour of 7.62x39mm tracer and API bullets in soft tissue

Area of Science:

• Forensic Ballistics
• Wound Ballistics
• Material Science

Background:

• Tracer and Armor Piercing Incendiary (API) bullets are military-grade ammunition.
• Some 7.62x39mm variants are occasionally used in criminal activities.
• Understanding their behavior in soft tissue is crucial for forensic analysis.

Purpose of the Study:

• To investigate the wound ballistics of tracer and API bullets in a soft tissue simulant.
• To compare the energy transfer and trajectory deflection of different bullet types.
• To identify how variations in API bullet design influence tissue damage.

Main Methods:

• Testing two types of tracer bullets and two types of API bullets.
• Utilizing a soft tissue simulant to mimic biological tissue interaction.
• Measuring energy transfer and deflection from the original trajectory.

Main Results:

• Tracer bullets showed similar energy transfer and greater deflection compared to API and Full Metal Jacket (FMJ) bullets.
• One type of API bullet yawed late, remained intact, and transferred minimal energy.
• The second API bullet type yawed early, disintegrated, and caused significant tissue disruption.

Conclusions:

• API bullet design critically influences wound severity and tissue damage.
• Variations in API bullet construction lead to distinct terminal ballistic performance.
• Forensic investigations should consider specific API bullet design when analyzing injuries.