Number: RS22888
Title: The Army's M-4 Carbine: Background and Issues for Congress
Authors: Andrew Feickert, Foreign Affairs, Defense, and Trade Division 
Abstract: The M-4 carbine is the Army's primary individual combat weapon for infantry units. The M-4 uses a direct gas impingement system that blows carbon from the fired cartridge back into the weapon's receiver, which can lead to weapon malfunctions. The U.S. Special Operations Command (USSOCOM) is replacing its M-4s with the Special Operations Combat Assault Rifle (SCAR). It is a modular weapon with a short-stroke piston system which eliminates carbon blow back that theoretically improves reliability. Some have questioned why the Army has not adopted the SCAR or another similarly designed weapon. A series of studies and tests of the M-4 and potential competitors have added to this debate.
Pages: 6
Date: Updated May 30, 2008