The FN SCAR (Fabrique Nationale Special Operations Forces Combat Assault Rifle)is a gas-operated (short-stroke gas piston) self-loading rifle with a rotating bolt. It is constructed to be extremely modular, including barrel change to switch between calibers. The rifle was developed by FN Herstal (FNH) for the United States Special Operations Command (SOCOM) to satisfy the requirements of the SCAR competition.
This family of rifles consist of two main types. The SCAR-L, for "light", is chambered in 5.56×45mm NATO cartridge and the SCAR-H, for "heavy", is chambered in 7.62×51mm NATO.
The SCAR-L and SCAR-H are known as the Mk16 and Mk17 in the US SOCOM
Civilian variants are available as the SCAR 16S and SCAR 17S