The M4 Carbine or the ArmaLite rifle (AR15), is a lightweight, gas operated, air cooled, magazine fed, shoulder fired weapon with a collapsible stock. It is the standard issue firearm for most units in the U.S. military.
Step 1: Clear the Weapon of Any Ammunition
To "clear" the M4 Carbine depress the bolt catch on the left side of the weapon while pulling the charging handle to the rear. Release the charging handle and lock it to the forward position, this will lock your bolt to the rear. Inspect the bore and firing chamber of the weapon to ensure no ammunition is present. The weapon is now clear.
NOTE: This is the most important step. Keep the barrel/mussel in a safe direction at all times.
Step 2: Separating the Upper and Lower Receivers
To separate the and lower receiver, remove the rear take down pin and forward pivot pin. You can now separate the upper receiver from the lower receiver.
Step 3: Remove the Buffer and Buffer Spring
Remove the buffer and buffer spring from the butt-stock of the weapon by, depressing the buffer spring retention pin. Ensure the hammer of the weapon is locked in place, you may have to push the hammer of the weapon down to remove the buffer and buffer spring assembly.
Step 4: Remove the Bolt Carrier Group
Remove the bolt carrier group from the upper receiver by pulling the charging handle to the rear and sliding the bolt carrier group to the rear, until it has been completely removed from the weapon.
Step 5: Remove the Charging Handle
Remove the charging handle, by depressing the charging handle release and pulling it to the rear and letting it drop from the slide grooves through the slide port.
Step 6: Remove the Bolt From the Bolt Carrier Group
Remove the bolt from the bolt carrier group by pulling the firing pin retaining pin out. Remove the firing pin, remove the cam pin and lastly, remove the bolt from the bolt carrier group.
Step 7: Reassemble Bolt Carrier
Reassemble bolt carrier group in the reverse order as previously described in step 6.
Step 8: Charging Handle
Place the charging handle in the charging handle slide of the upper receiver and slide it forward a 1/4 inch.
Step 9: Bolt Carrier Group in the Upper Receiver
Place the bolt carrier group in the upper receiver. Ensure the cam pin is properly aligned with the bolt carrier group.
To align the cam pin, pull the bolt away from the bolt carrier group until it is fully extended. Next, seat the gas tube receiver in the underside of the charging handle and slide the charging handle and bolt to the forward position of the upper receiver until it locks in place.
Step 10: Buffer Spring Assembly
Place the buffer spring assembly inside the buttstock of the weapon in reverse order of step three.
Step 11: Upper Receiver and Lower Receiver
Place the upper receiver and lower receiver together and depress the rear take down pin and forward pivot pin until both pins are flush with the receivers.
Step 12: Functions Check
Conduct a check in order to ensure proper operations:
Place selector lever on safe
Attempt to squeeze the trigger, weapon should not fire
Place selector lever on semi and squeeze the trigger
Hold trigger to the rear while charging the weapon
Release trigger, there should be a metallic click upon release
Place the selector lever on burst and then charge the weapon
Squeeze the trigger and hold trigger reward
Charge the weapone three times, release to hear metallic click
Charge weapon and place selector lever from burst to safe
Close ejection port cover
Step 13: Proper Stowage
Proper stowage posture for the M4 Carbine is with the hammer of the weapon "dropped".
To place the weapon in stowage posture, first clear the weapon as previously described in step two; place the selector lever from safe to semi and squeeze the trigger. The weapon is now in stowage posture.
NOTE: Leave ejection port cover open during stowage.
Step 14: Retrieving
When retrieving your M4 from stowage, clear the weapon! Place the selector lever on safe and close the ejection port cover.
Step 15: Employment
Employ the M4 Carbine, lock the bolt to the rear as described in the clearing procedures (step two), load a magazine of ammunition in the magazine well, release the bolt by depress the bolt release to chamber a cartridge of ammunition.
WARNING: Ensure that the weapon is pointed in a safe direction at all times now that it is loaded.