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54 Cards in this Set

  • Front
  • Back

What is the difference between the M4 and the M16?

The M4 is shorter

What is the purpose of the optical sight?

To improve shooter accuracy on point targets

What is the purpose of the shorter barrel?

To improve use inside a vehicle and allow rapid vehicle dismount

What are the characteristics of the M4?

Light weight, air cooled, gas operated, shoulder fired, magazine fed.

What is the caliber fired from the M4?

5.56mm NATO

What are the modes of fire for the M4?

Semiautomatic or 3 round burst

How much does the M4 weigh unloaded?

6.44 lbs

How much does the M4 weigh loaded?


How long is the M4 fully extended?

33 inches

How long is the M4 fully collapsed?

29.75 inches

How long is the M4 barrel with compensator?

15.5 inches

How many lands and grooves are there for the M4? What direction is the twist?

6 lands, 6 grooves, right hand twist

What is the twist ratio for the M4?

1 turn every 7 inches

What is the sustained rate of fire for the M4

12 to 15 rounds per minute

What is the semi-automatic rate of fire for the M4?

45 rounds per minute

What is the burst rate of fire for the M4?

90 Rounds per minute

What is the cyclic rate of fire for the M4?

700 - 970 rounds per minute

What is the maximum range for the m4?

3600 meters

What is the maximum effective range for a point target on the M4?

500 meters

What is the maximum effective range for an area target on the M4?

594 meters

What is the muzzle velocity of the M4?

2970 feet per second

What is the chamber pressure for the M4?

52,000 pounds per square inch

What type of locking system does the M4 have?

Rotating bolt

What is the purpose of the compensator?

To disperse the flash of the burning powder escaping the muzzle end of the weapon

What are the purposes of the cutouts on the top of the compensator?

To prevent muzzle climb in burst mode and prevent ground debris from kicking up while in the prone position

What are the barrel locking lugs?

They are the locking point for the bolt

What is the purpose of the barrel nut assembly?

To secure the barrel to the upper receiver

What is the purpose of the gas tube?

To channel the gas produced by firing the weapon towards the bolt carrier key

Describe the front sight post

It is a square, rotating sight post with for positions, and a spring loaded detent.

What direction do you move the front sight to move it up and down?

Clockwise = up
Counterclockwise = down

What piece of the M4 holds the hand-guards in place?

The slip ring

What are the rails called that can be attached to the M4?

Picatinny Rail or the military standard 1912 rail

What is the purpose of the forward assist?

To allow the manual forward advancement of the bolt carrier group

What is on the right side of the upper receiver behind the ejection port cover?

The integrated brass deflector

What are the characteristics of the M68 CCO?

It is a reflex(non telescopic) sight that utilizes a red (collimated dot) aiming reference.

How long is the M68 and how much does it weigh?

It is 5.1 inches and weighs 7 ounces.

What type of method of sighting does the M68 allow?


Is centering or focusing require on the M68 at distances greater than 50 meters?


What holds the M68 to the rail system of the M4?

The Torque limiting knob

What piece of the M68 CCO turns the optic on and off?

The rotary switch.

What is the BUIS?

Back up iron sights

How should you utilize the BUIS with the M68?

Turn the M68 off

What type of sight is the BUIS?

peep type

How is the BUIS adjustable?

It is adjustable for windage

What are the eight range settings for the BUIS?

200 ,300, 350, 400, 450, 500, 550, 600 meters

What is the purpose of the bolt carrier?

It works with the bolt cam pin to lock and unlock the bolt.

What is attached to the top of the bolt carrier that couples over the gas tube?

The bolt carrier key.

What has a dual purpose of retaining the bolt to the bolt carrier and rotates the bolt for locking and unlocking?

The bolt cam pin

How many positions does the buttstock have and what are they?

4: closed, 1/2 open, 3/4 open, and open

What are the two pins on the lower receiver?

The pivot pin (towards the barrel) and the takedown pin (towards the buttstock)

What houses the buffer?

The action spring

What are the two disconnectors inside the lower receiver? Where are the located?

The semi- automatic disconnector ( on the left next to the selector lever)

The burst disconnector (on the right with the magazine release button)

What lever is used to adjust the buttstock?

The lock lever release

What covers the bolt and the chamber when the bolt is forward?

The ejection port cover