FN SCAR

The FN SCAR (SOF (Special Operations Forces) Combat Assault Rifle) is a family of gas-operated short-stroke gas piston automatic rifles developed by Belgian manufacturer FN Herstal (FN) in 2004. It is constructed with modularity for the United States Special Operations Command (SOCOM) to satisfy the requirements of the SCAR competition. This family of rifles consists of two main types. The SCAR-L, for "light", is chambered in 5.56×45mm NATO and the SCAR-H, for "heavy", is chambered in 7.62×51mm NATO. Both types are available in Close Quarters Combat (CQC), Standard (STD), and Long Barrel (LB) variants.

In early 2004, United States Special Operations Command (USSOCOM) issued a solicitation for a family of Special Operations Forces Combat Assault Rifles, the so-called SCAR, designed around two different calibers but featuring high commonality of parts and identical ergonomics. The SCAR system completed low rate initial production testing in June 2007. After some delays, the first rifles began to be issued to operational units in April 2009, and a battalion of the U.S. 75th Ranger Regiment was the first large unit deployed into combat with 600 of the rifles in 2009.

The U.S. Special Operations Command later cancelled their purchase of the SCAR-L and planned to remove the rifle from their inventory by 2013. However, they will continue to purchase the SCAR-H version, and also plan to purchase 5.56 mm conversion kits for the SCAR-H, allowing it to substitute for the SCAR-L. As of 2015, the SCAR was in service in over 20 countries.

The SCAR is manufactured in two main versions; the SCAR-L ("Light") and SCAR-H ("Heavy"). The SCAR-L fires 5.56×45mm NATO rounds from STANAG (M16) magazines. The SCAR-H fires the more powerful 7.62×51mm NATO cartridge from proprietary 20-round magazines. Varied barrel lengths are also available for different purposes, such as close quarters battle or long-range engagements. The initial solicitation indicated that the SCAR-H would also be capable of being chambered in the 7.62×39mm M43 Kalashnikov cartridge, as well as the 6.8×43mm Remington SPC cartridge, however, FN is not currently offering this configuration, and the models have likely been cancelled.

The SCAR-L, designated Mk 16 by USSOCOM, was intended to replace the M4A1, the Mk 18 CQBR and the Mk 12 SPR that had been in service (before SOCOM decided to cancel the order for the Mk 16 Mod 0, see below), whereas the Mk 17 (SCAR-H) had been intended to replace the M14 and Mk 11 sniper rifles in use. However, the weapon will only supplement other weapons, while issuance remains of the operator's discretion.

The semi-automatic only Mk 20 Mod 0 Sniper Support Rifle (SSR) is based on the SCAR-H. It includes a longer receiver, a strengthened barrel extension and barrel profile to reduce whip and improve accuracy, and an enhanced modular trigger that can be configured for single-stage or two-stage operation together with either a folding or a non-folding precision stock.

The SCAR has two receivers: The lower is constructed of polymer, and the upper receiver is one piece and constructed of aluminum. The SCAR features an integral, uninterrupted Picatinny rail on the top of the aluminium receiver, two removable side rails and a bottom one that can mount any MIL-STD-1913 compliant accessories. The lower receiver is designed with an M16 compatible pistol grip, flared magazine well, and raised area around the magazine and bolt release buttons. The front sight flips down for unobstructed use of optics and accessories. The rifle uses a "tappet" type of closed gas system much like the M1 carbine while the bolt carrier otherwise resembles the Stoner 63 or Heckler & Koch G36.

The SCAR is built at the FN Manufacturing, LLC plant in Columbia, South Carolina, in the United States. Since 2008, FN Herstal has been offering semi-automatic versions of the SCAR rifles for commercial and law enforcement use. These are dubbed the 16S (Light) and 17S (Heavy), and are manufactured in Herstal, Belgium and imported by FN Herstal's U.S. subsidiary FN America of Fredericksburg, Virginia. FN America slightly modifies the rifles (supplying a U.S. made magazine and machining a pin in the magazine well) to be in compliance with U.S. Code before selling them.