Items you will need
Barrel vice or vice and towel
Crescent wrench or 3/4-inch wrench
Cloth or washrag
The AR-15 is a widely owned, generally semi-automatic assault rifle often equipped with a removable flash suppressor. A flash suppressor may need removal for several reasons, usually for upgrading, but the suppressor can take damage at the end of the muzzle and can bend or crack requiring removal. It's always a good thing to remove periodically for cleaning carbon build up.
Removing the Flash Suppressor on an AR-15
Always check the bullet chamber and remove the clip prior to maintenance. Protect the bluing on your rifle with cloths.
A rifle is a weapon. All accessories on the rifle are part of its function as a weapon. Use discretion when operating and consider the results of your actions for yourself and other people.
Check your chamber, remove the clip.
Open the barrel vice and place the AR-15 into the vice with the suppressor protruding. A barrel vice has a circular opening with additional padding meant to prevent stripping of the bluing, the oxidized chemical coating that protects the rifle from rust. This opening also helps prevent dents or twisting of the barrel. Or, if you don't have a barrel vice, lightly but securely place a towel around the barrel and place it in a standard vice. Be careful not to clamp too hard and damage the barrel. If you don't have a vice at all, placing a knee on the rifle, with the barrel sticking over the edge of a chair or table might work, depending on the tightness of the suppressor.
With the AR-15 secured in the vice, take your crescent wrench and widen the mouth of the wrench.
Place the washrag over the suppressor and tighten the open wrench around the base of the suppressor, fairly snugly. If you don't have a crescent wrench or if the suppressor is stuck too tight, a 3/4-inch wrench should fit the suppressor snugly, likely without the protecting of the washrag for the piece. So be careful if you are applying the metal of the wrench directly to the bluing.
You should be able to make a counter-clockwise turn on the suppressor and it should screw off the barrel, breaking loose with less than 25 lbs. of pressure, but no less than around 15 lbs. of pressure.
Clean the carbon build up from the barrel where the suppressor was mounted. This is a good time to clean and oil your whole rifle, especially if you are putting a new suppressor on.
Remove your rifle from the vice and you're good to go.
- Main Battle Assault Rifle image by Peter Orsaeo Sr from Fotolia.com