M2 Study Guide
 

Posted Sunday, June 25, 2006

What is the M2 .50 Cal machine gun used for?
Defend against low-flying hostile aircraft, support the infantryman in both attack and defense, destroy lightly armored vehicles, provide protection for motor movements, vehicle parks and train bivouacs, and reconnaissance by fire on suspected enemy positions

What is the weight of the M2 .50 Cal machine gun?
84 lbs

Which FM covers the M2 .50 Cal?
FM 3-22.65

What is the importance of correct headspace adjustment on the .50 Cal machine gun?
Incorrect headspace adjustment can cause a malfunction of the gun and lead to sluggish operation or failure to function freely.

What is the length of the barrel of the .50 Cal?
45 inches

What is the maximum range of the .50 Cal?
6,764 meters

What is the muzzle velocity of the .50 Cal?
3,050 ft per sec

What is the description of the .50 Cal, HB, M2 Machine Gun?
The Browning machine gun caliber .50 HB, M2 is a belt-fed, recoil-operated, air-cooled, crew-served machine gun. The gun is capable of single shot, as well as automatic fire, and operates on the short recoil principle.

What is the maximum effective range of the .50 Cal against point and area targets?

• Point targets Single shot- 1,500 meters
• Area shot- 1,830 meters

To control the rate of fire on the M2, the gunner may use what methods of fire?
 

• Single shot
• Slow
• Rapid
• Cyclic

Describe the Single Shot method of fire on the M2 .50 Cal.
Place the gun in the single-shot mode and engage the target with aimed shots. The machine gun is accurate out to 1,500 meters.

Describe the Slow method of fire on the M2 .50 Cal.
Slow fire consists of less than 40 rounds per minute, in bursts of five to seven rounds, fired at 10- to 15-second intervals.

Describe the Rapid method of fire on the M2 .50 Cal.
Rapid fire consists of more than 40 rounds per minute, fired in bursts of five to seven rounds, at 5- to 10-second intervals.

Describe the Cyclic method of fire on the M2 .50 Cal.
Cyclic fire is when the weapon fires 450 to 550 rounds per minute.

What is the length of the .50 Cal, overall?
Approximately 65.13 inches

What is the cyclic rate of fire of the M2 .50 Cal?
450-550 rounds a minute

What type of front sight does the M2 .50 Cal have?
A semi-fixed blade type with cover

What type of rear sight does the M2 .50 Cal have?
A leaf type rear sight graduated in both yards and mils

What are the common malfunctions of the M2 .50 Cal?

• Failure to function freely
• Uncontrolled automatic fire

What are the common stoppages of the M2 .50 Cal?

• Failure to feed
• Chamber
• Lock
• Fire
• Unlock
• Extract
• Eject
• Cock

What are the ten major components and assemblies of the M2 .50 Cal?

1. Barrel Group
2. Carrier Assembly
3. Back plate Group
4. Receiver Group
5. Bolt Stud
6. Cover Group
7. Barrel Buffer Body
8. Barrel extension group
9. Bolt Group
10. Driving Spring Rod Assembly

What are the proper procedures for performing immediate action on the M2 .50 Cal?

If machine gun fails to fire, take the following action:

1. Wait 5 seconds; a hangfire may be causing the misfire. In the next 5 seconds, pull the bolt to the rear (check for ejection and feeding of belt), release it, re-lay on the target, and attempt to fire. If the bolt-latch release and trigger are depressed at the same time, the bolt goes forward and the weapon should fire automatically.
2. If the gun again fails to fire, wait another 5 seconds, pull the bolt to the rear (engage with the bolt latch if applicable), and return the retracting slide handle to its forward position. Open the cover and remove the belted ammunition. Inspect the gun to determine the cause of stoppage.

A hangfire or cookoff can cause injury to personnel or damage to the weapon. To avoid these, the gunner must take the following precautions:

1. Always keep the round locked in the chamber the first 5 seconds after a misfire occurs. This prevents an explosion outside of the gun in event of a hangfire.
2. If the barrel is hot, the round must be extracted within the next 5 seconds to prevent a cookoff. When more than 150 rounds have been fired in a 2-minute period, the barrel is hot enough to produce a cookoff.
3. If the barrel is hot and the round cannot be extracted within the 10 seconds, it must remain locked in the chamber for at least 5 minutes, to guard against a cookoff.
4. Keep the gun cover closed during the waiting periods.