Medium Machine Gun Flashcards
Specifications of M240B
- Sus Rate: 100rpm
- Rapid Rate: 200rpm
- Cyclic Rate: 650rpm
- Muzzle velocity: 2,800 fps
- Max Range: 3,725m
- Eff. Range (Suppression): 1,800m
- Grazing Fire: 600m
8 Main Components of M240B
1) Barrel
2) Butt stock/ Buffer
3) Driving spring rod
4) Bolt and operating rod
5) Trigger-housing
6) Cover
7) Feed Tray
8) Receiver
Safety of M240B
- Located in the trigger-housing group
- Can’t place on safe when the bolt is forward
Functioning of M240B
- feeding
- chambering
- locking
- firing
- unlocking
- extracting
- ejecting
- cocking
5 types of ammo for M240B
- Dummy
- Blank
- Ball
- Tracer
- Armor-piercing
What is the proper headspace of the barrel for M240B
rotating the barrel-changing handle while counting the number of clicks heard. You should hear a minimum of 2 clicks but not more than 7
What is the purpose of the T&E mechanism
Provide controlled manipulation and the ability to engage predetermined target
What is the guide for barrel changing
- Sustained Rate for 10min
- Rapid Rate for 2min
2 common malfunctions of M240B
- Sluggish operation
2. Runaway gun
What is a Runaway Gun
when a gun continues to fire after the trigger is released; firing is uncontrolled
What is a Stoppages
any interruption in the cycle of functioning caused by
a. faulty action of the gun
b. defective ammunition
What is a Hang Fire
cartridge primer detonates after being struck by the firing pin but some problem with the propellant powder causes it to burn too slowly and delays the firing of the projectile
What is a Cook Off
heat of the barrel is high enough to cause the propellant powder inside the round to ignite even though the primer is not struck
2 common causes of stoppage of M240B
- Stuck cartridge
2. Ruptured cartridge
What is a Stuck Cartridge
swelling of the cartridge occurs when it fires. If the swelling is excessive, the cartridge will be fixed tightly in the chamber
