The US Special Operations Command (US SOCOM) issued a solicitation for the procurement of SOF Combat Assault Rifles (SCAR) on October 15th, 2003. This solicitation requested a new combat rifle, specially tailored for the current and proposed future needs of the US Special Forces, which are somewhat different from latest generic US Army requirements, which are being fulfilled by the newest Heckler-Koch XM8 assault rifle. The key difference in basic requirements between XM8 and SCAR is that, while XM8 is a single-caliber weapon system, tailored for 5.56x45mm NATO ammunition, the SCAR should be available in various different calibers.
Initial SOF requirements included two basic versions of SCAR system - the SCAR Light (SCAR-L), available in 5.56mm NATO, and the SCAR heavy (SCAR-H), which should be initially available in significantly more powerful 7.62x51 NATO chambering, and should be easily adaptable in the field to other chamberings. These other chamberings initially include the well-spread 7.62x39 M43 ammunition of the Soviet / Russian origins, and probably some others (like the proposed 6.8x43 Remington SPC cartridge, especially developed for US Special Forces).
The key idea of SCAR rifle system is that it will provide the Special Forces operators with wide variety of options, from short-barreled 5.56mm SCAR-L CQC variation, tailored for urban close combat, and up to long range 7.62x51 SCAR-H Sniper variant, as well as 7.62x39 SCAR-H, which will accept "battlefield pickup" AK-47/AKM magazines with 7.62 M43 ammunition, available during the operations behind the enemy lines. Both SCAR-L and SCAR-H shall be initially available in three versions, Standard (S), Close Quarters Combat (CQC) and Sniper Variant (SV). All these variants, regardless the caliber and exact configuration, will provide the operator with the same controls layout, same handling and maintenance procedures, and same optional equipment, such as sights, scopes, and other current and future attachments.
Late in 2004 US SOCOM announced, that the winner for the initial SCAR contracts is the FN USA, an US-based subsidiary of the famous Belgian company Fabrique Nationale Herstal. At the present time (Dec 2004) is is still unknown if the SCAR rifles will be made in USA or Belgium, but I suppose USA. The official XM / M designation is also not disclosed / assigned yet.
The FN SCAR rifles all based on the well proven 5.56mm FN FNC assault rifle. In all variants FN SCAR rifles feature gas operated, short stroke piston action with rotating bolt locking. Improved action has Kalashnikov AK-type bolt with two large locking lugs and fixed ejector. This system apparently is less sensitive to fine sand, dust and any other fouling inside the receiver, than any system with M16-type multi-lug bolt and plunger-type ejector. The receiver is made from two parts, upper and lower, connected with two cross-pins. Both parts are made of metal (probably lower receiver is made from aluminum alloy and upper receiver from stamped steel). It is still unclear if the SCAR system will have quick detachable barrels for various configurations and lengths (from short-barreled CQC to long-barreled SV), or the barrels will be swapped along with entire upper receiver.
The SCAR-H system also will have different type lower receivers, adapted to various types of ammunition and various types of magazines (i.e. 7.62mm NATO magazines and 7.62 M43 AK-type magazines, respectively). SCAR-L rifle will use improved M16-type magazines. The trigger unit with ambidextrous safety-fire mode selector switch will allow for single shots and full automatic fire, apparently with no provisions for limited-length bursts mode. The charging handle could be easily installed on either side of the weapon, so the upper receiver has respective cuts on both sides. Top of the upper receiver is covered by the full-length integral Picatinny rail (MIL-STD 1913); additional Picatinny rails are mounted on both sides and below the handguards. Side-folding polymer buttstock is adjustable for length of pull, and is shaped to proved positive cheek rest. SCAR rifles apparently will be fitted with removable, adjustable iron sights, with folding diopter-type rear sight on the receiver rail, and folding front sight on the gas block. Any additional type of sighting equipment, necessary for current tasks, including telescope and night sights, can be installed using MIL-STD 1913 compatible mounts. Current prototypes of SCAR rifles do not have bayonet mounts, and, probably, will never have one.
