General Flashcards
Where can you find weights and types of fillings of individual rounds of SAA?
DMP 1400-1000 Small Arms Ammunition.
For purposes of instruction, how do we categorize SAA?
By velocity - High and Low.
Why do we categorize SAA by Velocity instead of calibre?
Construction and characteristics vary with use & purpose, which in turn determines velocity and not an arbitrary measuring system.
DEFINE Small Arms Ammunition (SAA)
Ammunition for weapons such as pistols, rifles and machine guns below 20mm in calibre.
How is calibre for SAA categorised?
“The diameter of the barrel of the weapon measured between opposing lands of the barrel.”
A complete round of SAA is normally made up of four main component parts, what are they?
1 - Cartridge Case
2 - Initiation System
3 - Propellant Charge
4 - Bullet.
What 4 functions does a Cartridge Case provide?
1 - House propellant
2 - Incorporate initiation system
3 - Retain the bullet
4 - Provide rearward obturation.
What kind of propellant charge does a long range High Velocity round require?
A larger propellant charge.
Why are Cartridge Cases tapered and necked?
To avoid any extraction difficulties.
What is a distinguishing feature of Cartidge Cases for Low Velocity rounds?
The sides of the Cartridge Case may be almost parallel.
What is necking?
A means of housing the round in which a Cartridge Case has an enlarged diameter over most of its length before sharply reducing at the forward end to accept the bullet.
What influences the design of the forward end of the Cartridge Case?
The bullet which is to be accommodated.
What 3 key requirements must the forward end of the Cartridge Case meet?
1 - Stop the accidental removal of the bullet/projectile falling out in the magazine or barrel
2 - Seal against ingress of moisture
3 - Allow propellant gas pressure to build up sufficiently to achieve peak performance prior to release.
What 6 methods do we use for securing bullets?
1 - Press fit 2 - Indenting 3 - Coning 4 - Canneluring 5 - Stabbing 6 - Crimping
Which 2 methods of securing bullets are most widely used in Land Service ammunition?
Coning and crimping.
What 2 factors dictate the design of the base?
1 - The feed and extraction mechanism of the weapon
2 - the ignition system.
State the 4 types of base that have been used in service LSA.
1 - Rimmed
2 - Rimless
3 - Semi-rimless (OBSOLETE)
4 - Belted rimless (OBSOLETE)
How are rimless rounds positioned in the weapon?
By the shoulders of the Cartridge Case.
What is the advantage of a rimless base?
An extraction groove is machined around the base of the Cartridge Case to enable rounds to be fed into the breech of automatic weapons without becoming interlocked.
State the 3 types of initiation system in Land Service.
1 - Berdan (2 fire holes) (7.62mm)
2 - Boxer (1 fire hole) (5.56mm)
3 - Rimfire (0.22in)
State a type of SAA round that uses a Rimfire initiation system.
0.22in rounds.
State a type of SAA round that uses a Berdan initiation system.
7.62mm rounds.
State a type of SAA round that uses a Boxer initiation system.
5.56mm rounds.
Why are caps secured?
To prevent rearward escape of propellant gas (BLOW BACK).
State the 4 methods of securing caps.
1 - Push fit (Blank SAA)
2 - Ringing (British SAA)
3 - Burring (Proof Rounds)
4 - Punch stabbing (Foreign natures)
Bullet design is determined by what factors?
Ballistic requirements and the type and role of the bullet.
Why is boat-tailing included in designs?
1 - to eliminate drag
2 - to increase accuracy (although the effect of this is minimal at ranges below 600m).
State the in-service SAA natures.
Round 0.22in Round 0.338in Round 5.56mm Round 7.62mm Round 7.65mm Round 8.59mm Round 9mm Rounds .50in and 12.7mm
