Principals of Ballistics Flashcards
(22 cards)
Definition of Ballistics
Ballistics is the study of everything that happens to a projectile from the point of initial detonation until the projectile, or sub-projectile, comes to a complete stop.
4 Phases of Ballistics
- Internal Ballistics
- Transitional Ballistics
- External Ballistics
- Terminal Ballistics
Define Internal Ballistics
Includes projectile behavior from initiation of igniter until exit of round from the muzzle.
(Internal Ballistics)
Combustion Ingredients
Fuel
Oxygen
Heat
(Internal Ballistics)
2 Types of Obturation
- Projectile (Forward) Obturation
(Rotating/Drive Bands or Slip/J Bands) - Breech (Rear) Obturation
(Casing)
(Internal Ballistics)
Define In-Bore Balloting
Any transverse motion of a projectile in the gun tube.
(Internal Ballistics)
7 Causes of In-Bore Balloting
- Projectile center of gravity and offset from the bore center-line.
- Projectiles from manufacturer not perfectly concentric.
- Projectile/gun tube clearances may exist at projectile surface.
- Insufficient stiffness of the projectile or gun tube. Interface will exacerbate conditions caused by minimal balloting.
- Projectile wear produces or widens gaps (clearances) between the projectile or bourrelet surfaces and the gun bore.
- Gun tube curvature (including bore irregularities) exist in all gun tubes.
- Gas dynamics produce irregular pressures at projectile base
(Internal Ballistics)
Define Muzzle Brake
Muzzle brake relieves the pressure that builds up in the barrel when a gun is fired. The net effect is to reduce recoil.
(Internal Ballistics)
2 Methods of Muzzle Brake
- Directs the compressed air from in front of the projectile outward for the purpose of smoothing the flight of the round.
- Directs propellant gasses out to the sides after passage of projectile for the purpose of easing the transitional effects.
Define Transitional Ballistics
It is the initial motion of the projectile from when it exits the muzzle of the tube until propellant gasses are no longer affecting the projectile.
(Transitional Ballistics)
2 Parts of Transitional Ballistics
Initial yaw
Muzzle device effects (brakes, suppressors)
(Transitional Ballistics)
Define Muzzle Device
A muzzle device is an attachment on the end of the barrel with drilled holes and tapered vents that deflect pressure from propellant gasses
(Transitional Ballistics)
Muzzle Device Effects
Directs the gasses to sides, top, and bottom instead of straight forward
The net effect is reduced recoil.
Define External Ballistics
Defined as the motion of the projectile under the effects of gravity and air resistance.
(External Ballistics)
2 Types of Stabilization
Spin Stabilized
Fin Stabilized
Define Terminal Ballistics
Behavior of the projectile when it impacts a target.
(Terminal Ballistics)
2 Means of Achieving Penetration
Chemical Energy (CE) and Kinetic Energy (KE)
(Terminal Ballistics)
Define Kinetic Energy (KE)
A KE round punches through the armor of the target by concentrating the maximum force on a single point
(Terminal Ballistics)
3 Stages of Kinetic Energy (KE)
- Setup
- Penetration
- Perforation
(Terminal Ballistics)
Kinetic Energy (KE)
Define Setup
Setup – the initial contact that the penetrator has with the target where mass and velocity are concentrated at a very small point. Here, the penetrator may posture itself to follow the path of least resistance.
(Terminal Ballistics)
Kinetic Energy (KE)
Define Penetration
Penetration – The resulting force upon the target starts the penetration of the armor.
(Terminal Ballistics)
Kinetic Energy (KE)
Define Perforation
Perforation – when the penetrator has violated the armor and achieved the desired effects
