Editing M16 rifle (section)

===Muzzle devices===
Most M16 rifles have a barrel threaded in 1⁄2-28" threads to incorporate the use of a muzzle device such as a flash suppressor or [[sound suppressor]].{{sfnp|Sweeney|2007|p=67}} The initial flash suppressor design had three tines or prongs and was designed to preserve the shooter's night vision by disrupting the flash. Unfortunately it was prone to breakage and getting entangled in vegetation. The design was later changed to close the end to avoid this and became known as the "A1" or "bird cage" flash suppressor on the M16A1. Eventually on the M16A2 version of the rifle, the bottom port was closed to reduce muzzle climb and prevent dust from rising when the rifle was fired in the prone position.{{sfnp|Wieland|2011|p=200}} For these reasons, the U.S. military declared the A2 flash suppressor as a compensator or a muzzle brake; but it is more commonly known as the "GI" or "A2" flash suppressor.{{sfnp|Crawford|2003|p=85}}

The M16's [[Vortex Flash Hider]] weighs 3 ounces, is 2.25 inches long, and does not require a lock washer to attach to the barrel.{{sfnp|Hansen|2005|pp=28–32}} It was developed in 1984 and is one of the earliest privately designed muzzle devices. The U.S. military uses the Vortex Flash Hider on M4 carbines and M16 rifles.{{NoteTag|NATO Stock Number of NSN 1005-01-591-5825, PN 1001V{{sfnp|NATO Stock Number|2012}} }} A version of the Vortex has been adopted by the Canadian Military for the Colt Canada C8 CQB rifle.{{sfnp|Colt Canada|2012}} Other flash suppressors developed for the M16 include the Phantom Flash Suppressor by Yankee Hill Machine (YHM) and the KX-3 by [[Noveske Rifleworks]].{{sfnp|Sweeney|2007|pp=255–256}}

The threaded barrel allows sound suppressors with the same thread pattern to be installed directly to the barrel; however this can result in complications such as being unable to remove the suppressor from the barrel due to repeated firing on full auto or three-round burst.{{sfnp|Walker|2012|p=295}} A number of suppressor manufacturers have designed "direct-connect" sound suppressors which can be installed over an existing M16's flash suppressor as opposed to using the barrel's threads.{{sfnp|Walker|2012|p=295}}