GAU-21 Flashcards
Max Effective Range
1850m
Max Range
6500m
Muzzle velocity
2887 fps
Rate of fire
950-1100 rpm
Weapon stoppage procedures
1.) Weapon- trained on target (5sec)
2.) Weapon - charge (within the next 5 sec)
If bolt locks to the rear
3.) Weapon - fire (as req)
If weapon fails to fire
4.) Repeat steps 1-3
If weapon still fails to fire
5.) Fire/ safe selector - safe
6.) Weapon - clear
7.) Headspace/ timing - checked
8.) Feed chute - checked
If weapon cannot be locked to the rear
9.) Fire/ safe selector - safe
10.) Land as soon as practical
Runaway gun procedures
1.) weapon - trained on target
2.) Fire/ safe selector - safe
3.) weapon - clear
4.) Feed / chute ammunition - remove
Major components
Feed Cover
Auxiliary return Spring
Receiver
Trigger
Barrel Jacket/ Barrel
Bolt
Barrel Buffer
Backplate
Cardinal rules of aerial gunnery
Locate friendly forces
Engage the target in max effective range
Always assume the area is hot
Disengage the target before enemy’s effective range
Avoid Zap zone
Conserve ammo
Avoid flying in trail
Avoid target overflight
Take your time
Avoid flying parallel to terrain features
Know the situation
Cycle of operations
Feeding
Chambering
Locking
Firing
Unlocking
Extracting
Ejecting
Cocking
Feeding
When the next live cartridge in the ammunition belt is pulled over the belt holding pawls and onto the feed table
Chambering
Occurs with forward movement of the bolt
Locking
Occurs when the bolt locks to the barrel extension
Firing
Occurs when the firing pin makes contact with the primer
Unlocking
Occurs when the bolt is released from the barrel extension
Extracting
Two part process of removing a live cartridge from the ammunition belt, while simultaneously removing a cartridge case for the chamber
Ejecting
Forces the cartridge case out of the weapon
Cocking
Cocking lever of the bolt contacts the bolt latch bracket on the receiver, forcing the firing pin to retreat and lock back in the sear
Calls for cleared to fire
Tail is searching
Tail tally targets… going hot right side
CEASE FIRE CEASE FIRE CEASE FIRE
tail is safe
Calls when reloading
Tail is safe … reloading
Calls when arming
Tail gun is armed, ready to fire
Calls when dearming
Tail gun is safe and clear
100 rounds fired
Call when out of ammo
Tail is Winchester
Weapons free
Fire only at targets not identified as friendly IAW ROE
Weapons tight
Fire only at targets positively identified as hostile IAW ROE
Weapons hold
Fire only in self defense or in response to formal order
Barrel assembly
Comprises barrel and barrel extension assembly
Receiver assembly
Support, protect, and house various assemblies
Belt holding pawls and feed tray
Contribute to the correct feeding of the ammunition belt
Link chute assembly
guides the used links out of the GAU
Breech lock cam
Guides the breech lock
Extractor switch
Guides the front end of the extractor/ ejector assembly
Rear bracket sliding blocks assembly
Guides the aft portion of the weapon into the cradle assembly for mounting
Front sliding shoes assembly
Guides the fore portion of the weapon into the cradle assembly for mounting
Breech lock depressors
Force the breech lock down and off the breech lock cam, unlocking it from the bolt
Barrel jacket and flash suppressor assembly
Protects the barrel and minimize muzzle flash
Trunnion adapter
Secured the barrel jacket and flash hider
Manual cocking assembly
Pulls the bolt assembly to the rear of the receiver assembly into the cocked position
Bolt latch assembly
Holds back the bolt assembly on the open position. When fired the bolt latch is released by the bolt latch pawl
When in FIRE
The firing cam is in the outward position, the sear slide is forced down and moved into the sear forcing the firing pin to extend
Bolt assembly
Controls feeding, extracting, and ejecting operations, as well as operation of the firing pin
Barrel buffer assembly
Absorbs recoil energy of the barrel assembly
Feed cover assembly
Feed the ammunition belt from either side of the receiver assembly
Backplate assembly
Used to stop the bolt assembly at the end of its rearward movement and to absorb its remaining recoil energy
Backplate assembly
Used to stop the boat assembly at the end of its rear word, movement and to absorb it’s remaining recoil energy
Auxiliary spring return assembly
Assist the rod assembly when pushing the bolt assembly toward the front position to ensure there’s enough force to pull the ammunition belt correctly into the gun
Trigger assembly
Used to control the operation of the bolt latch to correctly hold back the bolt assembly at the rear clocked position and to release it
Counter recoil phase
The beginning of the cycle of operation. It is initiated by depressing the trigger assembly, which lifts the boat latch and allows the compress rod and spring assembly to expand and send the bolt forward to the battery position. The compressed barrel buffer assembly, also expands and sends the barrel and barrel extension forward into the battery position.
Recoil phase
Initiated by rapidly expanding gases generated as a bullet is being fired. These rapidly expanded gases, drive the barrel, extension, assembly and bolts to the rare of the weapon.
