A shooting can happen anywhere, a mall, down the street. Or even more scaring, in your own home. These guns are designed to put a bullets in the air in a short time, and if you are in a safe location, and have the ammunition, you may want to try some rapid fire. Most legal versions of assault rifles in the United States are semi-automatic.
So they only fire once each time the trigger is squeezed, but by holding the rifle and rapidly squeezing and releasing the trigger, you may be able to achieve a faster rate of fire. Take the gun down and clean it after it has cooled down. Whenever possible, always clean the barrel by inserting the cleaning rod into the breach (back) of the barrel, not the muzzle (front).
Depending on how the gas system is designed to operate, you may or may not need to clean the gas tube. Check for cleaning instructions specific to you rifle before you start, and beware small pins and springs. A magnet can help to keep track of these small parts, which are more common on modern AR designs.