The MK 17 Mod 0 SCAR-H is a 7.62mm x 51mm carbine / assault / sniper rifle that has been chosen by SOCOM to evenbtually replace a number of existing weapons used by US Special Operations Forces (SOF). The MK 17 comes in 3 flavors - the Standard, with 16 inch barrel, the CQC with a 13 inch barrel and the LB with a 20 inch barrel.