30mm Gun (GAU-23) Flashcards
Characteristics of the 30mm Gun (GAU-23):
Air-cooled Single Barrel Open Bolt Percussion-fired Chain-driven Belt fed Fires in either single or automatic-fire modes Located in the #1 gun station on the AC-130W Side eject modified 200 shots per minute (SPM) Firing rate (single or rapid) manually selected by gunner Powered by a 1hp 24 V dc motor
The 30mm gun provides fire against personnel, soft targets and light armor with ___________ _________
pinpoint accuracy
The 30mm may be preferred for _________ ________ _________ (______) because of its small fragmentation pattern
close air support (CAS)
The 30mm is capable of ______ shots per minute in the automatic setting
200
The 30mm consists of these 3 major components:
Barrel Assembly
Receiver Assembly
Feeder Assembly
The barrel assembly of the 30mm consists of these three parts
Barrel (with barrel alignment arrows)
Blast Diffuser
Shroud Bushing
Housing which supports various subassemblies of the 30mm:
Receiver Assembly
Part of the receiver assembly that has ring springs to absorb the recoil load and a hydraulic damper valve to control counter recoil
Recoil Mechanism
Part of the receiver assembly that stops guns in MISFIRE position if gun does not recoil
Mechanical Interlock
Part of the receiver assembly that transfers the recoil load to receiver mounting lugs which transfers load to the turret
Barrel Support Assembly
Part of the receiver assembly that is actuated by sear solenoid and sear push rod. Locks the gun in SEAR and MISFIRE positions by contacting master and sear links in the chain.
Sear Assembly
Part of the receiver assembly that restrains master and safety links from cycling backwards
Sear Catch Assembly
Part of the receiver assembly that converts rotational movement of the chain into linear movement (forward and aft). Rides in left side receiver and guide rod and houses the firing pin assembly
Bolt and Carrier Assembly
Part of the receiver assembly that is a mechanical counter actuated by recoiling breech. Does not record dry cycled rounds
Round Counter Assembly
Part of the receiver assembly that locks with the bolt and barrel to contain firing pressure
Breech Assembly
Part of the receiver assembly that contains the safety pawl and firing pin pawl
Track Assembly
Part of the track assembly that prohibits the firing pin from dropping when the safety is engaged. Safety handle cannot be disengaged with firing pin held against this.
Safety Pawl
Part of the track assembly that cocks the firing pin/prevents forward movement of the firing pin as the bolt carrier moves forward
Firing Pin Pawl
Part of the receiver assembly that is seated in the bolt carrier cross-slot to drive the bolt carrier. Held by the sear to stop the gun in the SEAR position
Master Link and Slider
Part of the receiver assembly held by the sear to stop the gun in the MISFIRE position if the round does not fire
Safety Link
Part of the receiver assembly that rotates, which raises and lowers the safety pawl
Safety handle and actuator
Part of the receiver assembly that consists of interchangeable nylon gears and shafts
Idler Sprocket Shaft and Idler Gears
Part of the receiver assembly that is a steel gear that drives the chain
Drive and Gear Retainer
Part of the receiver assembly that guides the bolt carrier
Guide rod
Part of the receiver assembly that holds the track and bolt carrier assembly in proper alignment to the breech
Receiver
Component of the 30mm that consists of two separate feed paths that pull ammo through feed chutes, strip the links, places round in bolt face, removes spent cartridge or unfired round from bolt face
Feeder Assembly
Lubricated and sealed portion of the feeder that contains gear train and electrical components of the feeder assembly
Feeder Drive Assembly
The right side of the feeder assembly contains the following four parts:
Feeder Drive Assembly
Forward Feed Area
Link Shield
Ejection Chute
Part of the feeder assembly that strips the round from the link, centers the round in the bolt face, and positions the spent case (or misfired round) in front of the ejector rod
Forward Feed Area
Part of the feeder assembly that prevents links from being ingested into the feeder rotor
Link Shield
Part of the feeder assembly that controls the spent case or misfired cartridge during forward ejection
Ejection Chute
The left side of the feeder assembly consists of the following three parts:
Forward Feed Assembly
Forward Feed Gate
Rotor Assembly
Part of the feeder assembly that guides the forward end of the cartridge case (neck)
Forward Feed Assembly
Part of the feeder assembly that guides the cartridge case from the feed path to the rotor path. It is spring loaded and self-centering
Forward Feed Gate
Part of the feeder assembly that feeds the new round into the bolt face and move spent case in front of the ejector rod during the bolt carrier rear dwell time.
Rotor Assembly
The rotor is indexed ____ of a revolution (____ degrees) during one gun cycle.
1/3
120
Part of the 30mm that provides visual indication of bolt position during gun cycle. It is only accurate if the drive shaft handle has not been lowered.
Bolt Position Indicator (BPI)
Part of the 30mm that signals the GCU that the gun has successfully reached the breech locked condition. It signals the GCU that the gun is in SEAR position.
Breech Lock Sensor
Part of the 30mm that actuates just past misfire to signal the GCU to stop the firing cycle or when trigger is released in automatic mode.
Normal Shutdown Sensor
Part of the 30mm Cycle of Operations in which the gun is locked in the SEAR position
Sear
Part of the 30mm Cycle of Operations in which the bolt is to the rear as the rotor places a new round in the bold face and the spent case is placed in front of the ejector rod
Feed
Part of the 30mm Cycle of Operations in which a live round is chambered into the breech/barrel and the spent case is ejected
Ram
Part of the 30mm Cycle of Operations in which the bolt is locked in the chamber and the firing pin is released
Fire
Part of the 30mm Cycle of Operations that consists of recoil, counter recoil and hang fire delay
Dwell
Part of the 30mm Cycle of Operations in which if no recoil is sensed, the bolt remains locked for an additional 0.5 seconds
Misfire
Part of the 30mm Cycle of Operations in which the bolt is unlocked and spent case is removed from the chamber
Extract
30mm cycle of operations:
Sear Feed Ram Fire Dwell Misfire Extract
In the 30mm cycle of operations, the gun stops in the __________ position following a single shot. While in automatic, the gun bypasses ________ and the cycle continues until the trigger is released
SEAR
sear
This part signals the gun control unit (GCU) that the gun is in the sear position
Sear Sensor (mounted behind BPI)
Recoiling components of the 30mm include:
Barrel assembly Breech Bolt and Components (cam pin, firing pin, firing pin sleeve, keeper) Recoil Mechanism
T.O. used for inspection of the 30mm
T.O. 1C-130(A)W-1
The purpose of the gun system inspection is to ensure that the gun system is in __________ ___________
operational condition
Safety procedures for inspecting the 30mm include:
Remove all jewelry prior to performing inspections
Always safe and clear weapon prior to inspection
Ensure no rounds exist in the chamber(s)