Forensic Ballistics

• The bullet is fired from the gun, leaving behind marks on its surface.
• Ballistics is the study of the motion of a projectile
• Ballistics as a science refers to a systematized body of knowledge
• Firearms (Gun) are weapons that discharge projectiles
• Firearms include rifles, revolvers, pistols, muskets, shotguns, carbines, and other deadly weapons
• Ammunition consists of a complete unfixed unit including a bullet, gunpowder, cartridge case, and primer
• A projectile refers to the object that passes through the barrel of a firearm
• Propellant is the explosive charge that projects a bullet from a gun
• Rifling is the composition of lands and grooves inside the barrel of a firearm
• Cartridge Case is a tubular container that holds together the bullet, gunpowder, and primer
• Interior Ballistics, also known as internal and initial ballistics, is the study of the projectile while it is still inside the barrel
• Stock-up refers to the slow exit of the bullet in the barrel, which can result in backfire or barrel breakage
• Hang fire refers to the delay of the explosion of the cartridge
• Ignition of the priming mixture can be affected by wet priming mixture, improperly fixed anvil, lack of vent or flash hole, and absence of priming mixture
• Combustion of gunpowder involves the crushing of the priming mixture, ignition of the priming mixture, primer flash, and the entry of gases into the vent or canal
• The expansion of the heated gas in the chamber causes the bullet and shell to separate due to pressure
• When a heated gas is developed by burning gunpowder, a tremendous pressure is produced in the chamber of the firearm
• Energy generated in ballistics is comparable to the impact of a falling person from a building
• Recoil is the rearward movement of the gun caused by the equal and opposite reaction of the gun against the forward movement of the bullet after the explosion
• The velocity of the bullet inside the barrel depends on the amount of gunpowder inside the shell
• Rotating of the bullet inside the barrel provides gyroscopic stability, especially in rifled bore barrels
• Engraving of the cylindrical surface of the bullet leaves metal fouling that can be removed with a steel brush
• Metal fowl refers to the metal strips left by a bullet inside, which can be removed with a steel brush
• Graphite is a lubricant substance used to prevent the adherence of metal fowl
• Transitional Ballistic, also known as Intermediate Ballistic, is the study of the projectile's behavior from the time it leaves the muzzle until the pressure behind the projectile is equalized
• Exterior Ballistics is the study of a bullet in flight from the time it leaves the barrel until it reaches the target
• Muzzle blast is the sound created at the muzzle point of the gun due to the sudden escape of gas coming in contact with the air in the surrounding atmosphere at the muzzle point
• Muzzle energy (ME) is the energy generated at the muzzle point
• Trajectory is the actual curved path of the bullet during its flight from the gun muzzle to the target
• Range is the straight distance between the muzzle and the target
• Velocity is the speed of the bullet or the rate of the speed of the bullet measured in feet per second (F/S)
• Air resistance (drag) is the capacity of the bullet to resist during its flight from the muzzle of the gun
• Keyhole shot is caused by yawing of the bullet resulting in hitting the target sideways, resulting in an oval-like entry of the bullet
• Pull of gravity refers to the downward movement of the bullet after reaching its maximum range
• Penetration refers to the entry and lodging of the bullet into the target
• Perforation refers to the entry and exit of a projectile to the target
• Ricochet is the bouncing of a projectile from a surface
• Two methods used to stabilize projectiles are spin, imparted by the rifling inside the barrel, and fins, which control the flight of projectiles fired from some smoothbore weapons
• Study of exterior ballistics requires an understanding of Physics (particularly Newton's laws of motion), Aerodynamics, Mathematics (including calculus), Gyroscopy, and some meteorology
• Shot Ballistics deals with the attributes and properties of shots and pellets, and it refers to the study of shots from smoothbore firearms like shotguns and muskets