Two years after completing field testing, the new American assault rifle, SCAR, has been issued to a battalion of U.S. Army Rangers, who are headed for Afghanistan. SCAR (Special operations forces Combat Assault Rifle) was a SOCOM (Special Operations Command) effort to develop a new assault rifle that had some of the characteristics of the (now abandoned) U.S. Army XM-8 rifle. SOCOM had the money, and authority to develop their own weapons. And SCAR is mainly for use by SOCOM troops.
Here is a training video: