Ballistics Flashcards
What is ballistics?
The scientific study of the motion of projectiles
4 phases of ballistics
Interior (Internal)
Intermediate
External
Terminal
What is internal ballistics?
The scientific study of the operating process
within the gun from the moment that the
propellant is ignited until the projectile leaves
the barrel
What are the objectives(goals) of internal ballistics?
Launch the projectile safely
Consistent performance between shots
Achieve the highest possible muzzle velocity
What is the all burn point?
Where all the propellant has been consumed
What is explosion heat (Qex)?
the amount oh heat liberated in the combustion of 1kg of propellant
Define Pioberts law
The surface of a Burning propellant recedes layer by
layer in a direction normal to the surface.
What is intermediate ballistics?
The study of the transition from internal to external ballistics that occurs in the vicinity of the muzzle
What are the 2 parts of bottle shock?
Barrel shock - sides
Mach disc - front
What are the types of flash?
Pre-flash Primary flash Muzzle glow Intermediate flash Secondary flash
What are the three main ways to minimize muzzle flash?
Muzzle devices ( flash suppressors)
Type of propellant
Propellant additives
What are the 3 main reasons for muzzle devices?
Reduce recoil
Suppress flash
Decrease report
What are the 3 types of silencers?
Blast absorption
Blast dissipation
Blast containment and controlled release
What are the properties of a projectile?
Mass
Caliber
Nose Shape
Spin Rate
What are the properties of the atmosphere
Air Density
Temperature
Pressure
What is trajectory?
The path taken by the C of G of the projectile
What is drag co-efficient? (Cd)
Drag coefficient (C d ) quantifies the drag of an object through a fluid (Air or Water).
What is yaw?
angle between axis of projectile and that of the velocity vector or trajectory.
What are the four burning characteristics of propellant composition?
Burning rate
Pressure index
Force constant
Co-volume
What are the six areas of distribution of energy when the gun is fired?
Projectile, transitional and rotational. heat in the gas Gun recoil Driving band engraving and overcoming Unburnt charge and gases Heat in the gun
What are the 4 phases of internal ballistics?
Charge ignition
Combustion prior to projectile motion
Combustion up to the all burn point
Gas flow and projectile motion after all burn point to muzzle
How can the round to round regularity of muzzle velocity be improved?
If burning finishes while the shell is still well back in the bore
The muzzle gas flow field during firing consists of what two phases?
The precursor blast field that proceeds the projectile exit from the muzzle
The main blast field that follows as high pressure propellant gases are ejected into the air
What is a bore evacuator?
It prevents propellant fumes from entering crew compartments.
Works by creating pressure diffentials during and after firing
High pressure propellant gases are stored in the evacuator as the round passes through the barrel.as the round exits the muzzle, the high pressure gases flow out the muzzle. This may increase the secondary flash
What are the four drag forces?
Skin friction
Pressure drag
For body drag
Excrescence drag
Define ballistic co-efficient.
The measure of a projectiles ability to overcome drag
What are two way of reducing the effect of base drag?
Boat tailing
Base bleed
What forces act on a projectile?
Drag Pressure Yaw Gravity Velocity Roll
How do most flash suppression devices reduce flash?
Break up the barrel shock
Mach disc
What can you use to reduce blast in small caliber weapons like pistols?
Silencers
Burning characteristics of propellant granule
Ballistic size
Form function
What is muzzle press
Peak over pressure at the mizzle upon breakage of the projectile bore seal
What are the 4 ballistic abnormalities?
Cold gun affect
Occasion to occasion affect
Order of fire
Ballistic hump
What are the ways to overcome the forces of a projectile
Nose shape
Base shape
Base bleed
