The AR15 is a semi-automatic assault rifle that mimics the M4 and M16A2 service rifles used by the U.S. Military. The AR15's overall design and operation is the same as its military-issued brethren, being a gas-operated, air-cooled, shoulder-fired weapon, with adjustable front and rear sights. The AR15 upper receiver consists of the bolt carrier group, barrel and charging handle. These components can be removed from the weapon frame without the aid of tools, and only requires the removal of two take-down pins to separate the upper and lower receiver. You should consult your AR15 owner's manual for detailed cleaning instructions after disassembly of the upper receiver.
1. Remove the magazine, pull the charging handle to the rear and visually inspect the chamber to ensure that the weapon is completely unloaded. Ensure that the weapon selector switch is on the "safe" setting.
2. Locate the rear take-down pin located just above the selector switch. Depress the pin either by pushing in with your knuckle, or a dummy round. Push the pin from left to right as far as it will go. The pin will not come out completely, but will release the rear hinge holding the upper and lower receiver together.
3. Depress the front pivot pin located above the magazine well. The pin will not come out completely, but, after depressed, will disengage the upper and lower receiver completely.
4. Pull the charging handle to the rear as you normally would when cocking the weapon. This action will slide out the bolt carrier group.
5. Pull back, then up on the charging handle to remove the charging handle from the upper receiver.
6. Remove the firing pin retainer from the bolt. This is a spring-loaded sprocket located on top of the bolt. Push it in then twist counterclockwise to remove it. Push the bolt forward in the carrier, then tip it upside down and the firing pin will fall out.
7. Remove the bolt cam-pin from the bolt-end of the carrier. The bolt end is recognizable by a cogged wheel on one end. Turn the cam-pin 1/4 turn counterclockwise then lift up to remove it. Slide the bolt out of the carrier after removing the cam-pin.
- Main Battle Assault Rifle image by Peter Orsaeo Sr from Fotolia.com