FN SCAR

The Special Operations Forces Combat Assault Rifle (SCAR)[11] is a gas-operated (short-stroke gas piston)[9] self-loading rifle with a rotating bolt and a firing rate of 625 rounds/min.[10] It is constructed to be extremely modular, including barrel change to switch between calibres. The rifle was developed by FN Herstal (FNH) for the United States Special Operations Command (SOCOM) to satisfy the requirements of the SCAR competition.[12] This family of rifles consist of two main types. The SCAR-L, for "light", is chambered in the 5.56×45mm NATO cartridge and the SCAR-H, for "heavy", fires 7.62×51mm NATO. Both are available in Long Barrel and Close Quarters Combat variants. The FN SCAR systems completed low rate initial production testing in June 2007.[13] After some delays, the first rifles began being issued to operational units in April 2009, and a battalion of the US 75th Ranger Regiment was the first large unit deployed into combat with 600 of the rifles in 2009.[2] The US Special Operations Command later cancelled their purchase of the Mark 16 (or MK 16) SCAR-L and planned to remove the rifle from their inventory by 2013. However, they will continue to purchase the Mk 17 SCAR-H version, and also plan to purchase 5.56 mm conversion kits for the Mk 17, supplanting the loss of the Mk 16.[14] As of early 2015, the FN SCAR is in service in over 20 countries.

Overview
U.S. Air Force Special Tactics Officer with FN SCAR in Afghanistan in 2010

The SCAR is manufactured in two main versions; Light (SCAR-L, Mk 16 Mod 0) and Heavy (SCAR-H, Mk 17 Mod 0). The L version fires 5.56×45mm NATO using improved STANAG (M16) magazines. The H fires the more powerful 7.62×51mm NATO from a newly designed 20-round magazine. Different length barrels will be available for close quarters battle and for longer-range engagements. The initial solicitation indicated that the SCAR-H would also be chambered for the 7.62×39mm M43 Kalashnikov cartridge and 6.8×43mm Remington SPC cartridge. However, FN is not currently offering other calibers.

The Mk 16 Mod 0 was intended to replace the M4A1, the Mk 18 CQBR and the Mk 12 SPR currently in SOCOM service, before SOCOM decided to cancel the order for the Mk 16 Mod 0 (see below). The Mk 17 Mod 0 will replace the M14 and Mk 11 sniper rifles. However, the weapon will only supplement other weapons while issuing remains at the operator's decision.

The Mk 20 Sniper Support Rifle is based on the 7.62mm Mk 17 rifle. It includes a longer receiver, a beefed up 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.[16]

The SCAR has two receivers: The lower is constructed of polymer, and the upper receiver is one piece and constructed of aluminum.[17] 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. It has a polymer lower receiver with an M16 compatible pistol grip, flared magazine well, and raised area around 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 FNH USA, Fredericksburg, Virginia, United States.[18][19] FNH USA 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.

In July 2007, the US Army announced a limited competition between the M4 carbine, FN SCAR, HK416, and the previously-shelved HK XM8. Ten examples of each of the four competitors were involved. During the testing, 6,000 rounds apiece were fired from each of the carbines in an "extreme dust environment". The purpose of the shootoff was to assess future needs, not to select a replacement for the M4.[20]

During the test, the SCAR suffered 226 stoppages. Since a percentage of each weapons' stoppages were caused by magazine failures, the FN SCAR, XM8 and HK416 performed statistically similarly.[21] The FN SCAR ranked second to the XM8 with 127 stoppages, but with fewer stoppages compared to the M4 with 882 stoppages and the HK416 with 233. This test was based on two previous systems assessments that were conducted using the M4 Carbine and M16 rifle at Aberdeen Proving Ground in 2006 and the summer of 2007 before the third limited competition in the fall of 2007. The 2006 test focused only on the M4 and M16. The Summer 2007 test had only the M4, but increased lubrication. Results from the second test resulted in a total of 307 stoppages for the M4 after lubrication was increased, but did not explain why the M4 suffered 882 stoppages with that same level of lubrication in the third test.[21][22]

The SCAR was one of the weapons displayed to U.S. Army officials during an invitation-only Industry Day on 13 November 2008. The goal of the Industry Day was to review current carbine technology for any situation prior to writing formal requirements for a future replacement for the M4 carbine.[23][24]

HAMR IAR
In 2008, a variant of the FN SCAR—the Heat Adaptive Modular Rifle (HAMR)—was one of four finalist rifles for the Infantry Automatic Rifle (IAR) competition. The IAR was a United States Marine Corps requirement for a lightweight automatic rifle for squad automatic rifle use.[25] The FN entry was different from existing SCAR versions in that it combined closed bolt operation (fires from bolt forward/chambered cartridge) with open bolt operation (fires from bolt to the rear, no chambered cartridge), switching automatically from closed to open bolt as the weapon's barrel heats up during firing. There have been previous firearms with mixed open/closed bolt operation, but the automatic temperature-based operating mode switch is an innovation. The IAR competition was expected to result in Marine Corps procurement of up to 6,500 automatic rifles over five years,[26] but eventually the SCAR variant was passed over in favor of the Heckler and Koch HK416 rifle,[27] later designated as the M27.[28]

FNAC
The SCAR was one of the competing weapons in the Individual Carbine competition which aimed to find a replacement for the M4 carbine.[29] A variant of the SCAR was entered into the competition, known as the FNAC (Advanced Carbine). The weapon is similar to the SCAR Mk 16 Mod 0 but with modifications including a 140 g (0.3 lb) weight reduction resulting in a loaded weight of 3.61 kg (7.95 lb), a bayonet lug for an M9 bayonet (which the Mk 16 does not have), a rail mounted folding front iron sight instead of the gas block mounted sight, and a non-reciprocating charging handle.[30][31][32] The competition was cancelled before a winner was chosen.[33]

Enhanced Grenade Launching Module
Introduced in 2004 as an addition, the Enhanced Grenade Launching Module[34] (EGLM), officially referred to as the FN40GL, or Mk 13 Mod 0, is a 40 mm grenade launcher based on the 'GL1' designed for the F2000. The FN40GL is marketed in both an L (Light) and H (Heavy) model, for fitting the appropriate SCAR variant.[35] The EGLM system features a double-action trigger and a swing-out chamber. These offer two advantages over the M203 system, the first being that the launcher does not need to be re-cocked if the grenade does not fire, and the latter being that longer grenades can be used. Like the M203, the FN40GL uses the same High-Low Propulsion System.

The FN40GL is deemed a third generation grenade launcher, meaning it is multifunctional: it can be used mounted to the rifle or as a standalone system; it is manufactured using a number of materials like aluminum, composites, and polymers; the breech opens to the side for use of longer 40 mm rounds including less-lethal; and it is mounted on the bottom accessory rail instead of requiring specialized mounting hardware. The FN40GL is attached to SCAR rifles on the bottom rail with a trigger adapter and dual locking clamp levers on the launcher, limiting the ability to integrate with other rifles. Barrel length is 240 mm (9.6 in), and is unique in that it is the only system where the barrel can swivel to the left or right for loading, while other breech loading launchers pivot specifically to one side. This enhances its ambidextrousness, making its easy for a left-handed operator to load under fire. The standalone stock assembly has the FN40GL mounted to the bottom rail as with the rifle, but still has 3 o’clock, 6 o’clock, and 9 o’clock rail positions for other accessories. This is mainly during non-lethal uses for other mounted additions like LED lights and laser dazzlers. The trigger is placed lower than normal for operation with the user's middle finger, while keeping their trigger finger free to use the rifle. The double-action trigger is long and heavy to prevent easily and unintentionally firing a round under stress.[36]

U.S. Navy SEALs conducting training with SCAR rifles

Acceptance
U.S. Navy SEAL with a SCAR-H rifle

The SCAR was selected in 2004 out of the Special Operations Forces (SOF) Combat Assault Rifle Program. The MK 16, MK 17, and MK 13 were officially designated as operationally effective (OE), operationally suitable (OS), and sustainable as a result of a 5-week Field User Assessment conducted by operational SOCOM forces in late 2008. These SCAR variants began fielding in April 2009.[37] On 4 May 2010, a press release on FNH USA's official website announced the SCAR Acquisition Decision Memorandum was finalized on 14 April 2010, moving the SCAR program to the Milestone C phase. This was an approval for the entire weapons family of the Mk 16 SCAR Light, Mk 17 SCAR Heavy, and the Enhanced Grenade Launcher Module.[38]

In late October 2010 SOCOM approved full-rate production of the Mk 20 sniper variant of the SCAR, with fielding beginning in mid-May 2011.[16]

Purchase
On 23 January 2004, US SOCOM issued a Request for Proposal (RFP) for solicitation USZA22-04-R-0001. The following amounts were projected for procurement:[2]

Mk 16 Cancellation/Mk 17 Preference
U.S. Navy SEAL with a SCAR-H rifle

On 25 June 2010 SOCOM announced that it was canceling the acquisition of the Mk 16 citing limited funds and a lack of enough of a performance difference in another 5.56 mm rifle to justify the purchase. Remaining funds would be expended for the Mk 17 7.62×51mm version and the Mk 20 sniper variant. At the time, SOCOM had bought 850 Mk 16s and 750 Mk 17s.[39] SOCOM had operators turn in their Mk 16s and is not keeping them in the inventory, but started developing a conversion kit for the Mk 17 to make it capable of firing 5.56 mm rounds.[40]

"FNH USA believes the issue is not whether the SCAR, and specifically the [originally contracted] MK 16 variant, is the superior weapon system available today...it has already been proven to be just that...recently passing Milestone C and determined to be operationally effective / operationally suitable (OE/OS) for fielding. The issue is whether or not the requirement for a 5.56 mm replacement outweighs the numerous other requirements competing for the customers’ limited budget.  That is a question that will only be determined by the customer".[41] FN Herstal though had refuted that the Mk 16 was being dropped from the inventory and stated that the 5.56 mm variant will be retained by SOCOM, and that "The choice between the 5.56 and the 7.62 caliber will be left to the discretion of each constitutive component of USSOCOM's Joint Command (e.g. SEALs, Rangers, Army Special Forces, MARSOC, AFSOC) depending on their specific missions on today's battlefield".[42]

FNH USA's claim contradicted the official announcement from SOCOM and they did not reverse their decision. SOCOM decided to procure the 7.62 mm Mk 17 rifle, the 40 mm Mk 13 grenade launcher, and the 7.62 mm Mk 20 Sniper Support rifle variants of the Special Operations Forces Combat Assault Rifle (SCAR) manufactured by FN. SOCOM would not purchase the 5.56 mm Mk 16. At that point the individual service component commands within SOCOM (Army Special Operations Command, Naval Special Warfare Command, Air Force Special Operations Command, and Marine Corps Forces Special Operations Command) would or would not still buy the 5.56 mm Mk 16 SCAR for some or all of their respective subordinate units even with overall US Special Operations Command opting not to.[43]

SOCOM began removing the Mk 16 from their inventory at the end of 2011, and most units will have the rifle completely out of their service by the end of 2013. To maintain the SCAR as a small caliber weapon, they are procuring conversion kits for the Mk 17 battle rifle to make it fire 5.56 mm rounds.[44] The presolicitation for the SCAR program originally called for one rifle that could be adapted to fire multiple calibers including 5.56 mm, 7.62 mm, and 7.62×39mm. When requirements were finalized, the decision was made to separate the 5.56 mm and 7.62 mm weapons into two platforms because converting the medium caliber platform to fire small caliber bullets created an assault rifle heavier than the M4 carbine. After fielding, operators reversed the previous decision and called for a SCAR platform that could change calibers. The Mk 17 was chosen to be scaled down because it had a larger receiver for the 7.62 mm round, and so the 5.56 mm Mk 16 could not be scaled up to chamber the larger round. The 5.56 conversion kit was finalized in late 2010 and orders began in mid-2011.[45]

On 9 December 2011, the Naval Surface Warfare Center Crane Division released a sole source 5 year IDIQ procurement notice for the Mk 16 Mod 0 (SCAR-L), Mk 17 Mod 0 (SCAR-H), Mk 20 Mod 0 (SSR), and MK 13 Mod 0 (40mm EGLM) from FN to sustain inventory levels.[46][47] Navy special operations forces procures their firearms through SOCOM and fielded the Mk 16 more than any other unit.[39]