Editing M16 rifle (section)

===M4 carbine===
{{Main|M4 carbine}}
[[File:SCRange20034344940.jpg|thumb|right|An [[M4 carbine#M4A1|M4A1 carbine]] (foreground) and two M16A2s (background) being fired by U.S. Marines during a [[live fire exercise]]: though adopted in the 1990s and derived from the M16A2, the M4 carbine was part of a long line of short-barreled [[AR-15]] used in the U.S. military]]

The M4 carbine was developed from various outgrowths of these designs, including a number of {{convert|14.5|in|mm|0|adj=on}}-barreled A1 style carbines. The XM4 (Colt Model 720) started its trials in 1984, with a new {{convert|14.5|in|mm|abbr=in}} "stepped" barrel, case deflector, M16A2 rear sight, and a new elliptical handguard. The weapon became type classified as the "Carbine, 5.56mm, M4" in 1991. Officially adopted as a replacement for the M3 "Grease Gun" (and the [[M9 pistol|Beretta M9]] and M16A2 for select troops) in 1994, it was used with great success in the Balkans and in more recent conflicts, including the [[War in Afghanistan (2001–2021)|Afghanistan]] and [[2003 invasion of Iraq|Iraq]] theaters. The M4 carbine has a three-round [[Burst mode (firearm)|burst]] firing mode, while the M4A1 carbine has a [[automatic firearm|fully automatic]] firing mode. Both have a Picatinny rail on the upper receiver, allowing the carry handle/rear sight assembly to be replaced with other sighting devices.

====M4 Commando====
{{Main|CAR-15}}
Colt also returned to the original "Commando" idea, with its Model 733, essentially a simplified XM177E2 with the flash hider/sound moderator deleted and replaced with a normal birdcage-style flash hider. Over the different production runs Colt would assemble the guns with whatever parts were on hand, sometimes leading to the mixing of different M16, M16A1, M16A1E1, and M16A2 features on individual guns.