A U.S. Army Ranger with the 2nd Battalion, 75th Ranger Regiment takes aim with a SCAR-L MK 16 CQC during tast force training, 2013.
The MK16 CQC is a 5.56mm x 45mm carbine in limited use within Special Operations Command (SOCOM) units, including the 75th Rangers.
SOCOM only ever bought a total of 1000 MK16s.
The CQC variant is fitted with a 10 inch barrel and is designed for close quaters combat operations.
more info: MK 16 SCAR-L