SA5 Flashcards
What is ballistics?
The scientific study of the motion of projectiles
What is internal ballisics
The scientific study of the operating processes within the gun from the moment that the propellant is ignited until the projectile leaves the gun.
What are the objectives of internal ballistics
Launce the projectile safely
Consistent performance between shots
Achieve highest possible muzzle velocity
What are the four parts of a gun
Breech
Chamber
Barrel
Muzzle
What are the phases of internal ballistics
Charge ignition
Combustion prior to projectile motion
Combustion up to all burnt point
Gas flow and projectile motion after all burnt point to muzzle
Characteristics of burning rate for propellants
Is the rate at which a granule reduces in size as the burning of that granule occurs on all sides
What is force constant for propellants
Measure of pressure which a unit mass propellant produces in a fixed volume
What is the difference between single and double based Propellants burn times and pressures
Single base - single burn with a high pressure for short period
Double based - double burn at low pressure for a longer period
What is silver point
In multi tubular propellant, the holes expand to meet each other creating silvers of unburnt propellant. This then becomes a degressive burn
How long does initiation to muzzle exit take
Less than 15 milliseconds
What is pioberts law?
Surface of a burning propellant reduces layer by layer in a direction normal to the surface
How can round to round muzzle velocity be improved
If all burn point occur whilst rounds are still in the bore
What are six areas that energy is distributed when the gun is fired?
Projectile
Heat in the gas and gun
Gun recoil
Driving band engraved
unburnt charge/gas
What is the effect of an increase in charge weight
Pressure increase, Muzzle velocity increase, all burn point moves back
What is intermediate ballistics?
Is the study of the transition from internal to external ballistics
What is a blast shock wave?
The outgoing noise from High pressure gas that is released from the muzzle
What are the two precursor fields?
Bottle shock which consists of barrel shock being the sides and mach disc being the front.
What are the two types of shock
Barrel shock and bottle shock
What can cause yaw in a projectile?
Forces behind the projectile leaving the muzzle can cause it to yaw at shock waves catch up to the projectile
What are the four types of muzzle flash?
Pre-flash
Primary flash
Muzzle glow
intermediate flash
secondary flash
What is muzzle flash
Light emitted in vicinity of the muzzle by hot propellant gasses and chemical reaction that occur as the propellant gases mix in the air
What are flash reduction methods?
Muzzle devices
Type of propellant
Propellant additives
What are the three main reasons for uses muzzle devices?
Reduce recoil
Supress flash
Decrease report
What are the three types of flash supressors
Conical tube
Slotted tube
Bar type
