MK16 and MK17 – the assault rifles of the US Special Operation Forces

PANAGYURISHTE, (BM) – Perhaps FN SCAR can be described as one of the best recent developments in terms of creating a modern automatic rifle that could quickly turn into a light machine gun, semi-automatic sniper or short-barreled assault rifle for working in narrow spaces. But let’s not get ahead of ourselves, first things first.

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Special Operations Forces Combat Assault Rifle – a rifle designed for special operations forces, later named FN SCAR, the abbreviation for the name of the weapon was as follows: FN – Fabrique Nationale, a brand that does not need comments, S – Special Operations Forces, C – Combat, A – Assault, R – Rifle. FN SCAR. In the beginning, as soon as the competition was announced, the competition itself was called this abbreviation – SCAR.

This weapon was created as the most universal system, for use in any conditions and for hitting targets both at long distances and practically point-blank when cleaning buildings. Of course, it was envisaged the creation of a whole series of FN SCAR family, which would meet both the indicated extremes in application and intermediate methods of application.

The development was carried out in 2003, after the FN (FNH USA Inc.) state branch received an order for weapons of such a plan that would be able to fulfill the functions of most types of small arms with simple manipulations with the change of barrels and some other details (for example, the installation of an optical sight, if a long barrel is installed, or a collimator for close combat when a short barrel is set).

Other world-famous giant arms companies participated in the competition to create new automatic weapons for fighters of the fairly well-known US special forces US SOCOM, but the development option FNH USA Inc. was chosen Immediately in two versions, named Mark 16 (Mk.16 SCAR-L) and Mark 17 (Mk.17 SCAR-H).

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The weapon was created in two versions – FN SCAR L, where the letter “L” meant “Light” – “Light” and FN SCAR H, where “H” meant “Heavy” – “Heavy”. The difference was in the ammunition used, namely the FN SCAR L automatic rifle used 5.56×45 NATO cartridges, which was why it was called “light.” A more powerful version of the FN SCAR H fired NATO 7.62×51 rounds, which are much longer range more powerful and more stable than 5.56 mm bullets.

Therefore, the 7.62 mm caliber rifle was called “heavy.” In the context of this topic, the words “Light” and “Heavy” do not imply the mass of these two automatic rifles, because the difference in mass is insignificant.

The difference in power. FN SCAR L has a relatively weak return and the bullets from this rifle quickly lose energy, especially when passing through various obstacles, even insignificant ones (thin branches, foliage, shrubs). But with an automatic rifle FN SCAR H, the situation is somewhat different.

The energy of the 7.62×51 cartridge bullet is incomparably more powerful than 5.56 mm, respectively, and the recoil of this weapon was much stronger, which made it difficult to fire bursts, especially without focus and from unstable positions.

The system is the assault rifle itself and the FN40GL underbarrel grenade launcher, designed specifically for this weapon model. The grenade launcher can be installed on both versions of the FN SCAR rifles, also the pistol grip and shoulder rest are attached to the grenade launcher, after which the underbarrel grenade launcher can be used independently as a separate weapon from the rifle.

This weapon system was recognized as the winner of the competition in December 2004, and at the moment it is adopted by the American rangers. These rifles enter the active units of the American special forces in Iraq and Afghanistan, where they showed their very high combat effectiveness, versatility and ease of use, but, on the other hand, showed sensitivity to pollution, but much less sensitivity than automatic rifles of the M16 family.

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It is assumed that in the foreseeable future, the Mk.16 (FN SCAR L) and Mk.17 (FN SCAR H) rifles will replace weapons such as Colt M4 automatic carbines and 5.56 mm automatic rifles of the M16 series, and more powerful rifles M14 and Mk.25 (sniper rifle) chambered for NATO 7.62×51.

The work of parts and mechanisms, automation.

FN SCAR automation is based on a gas engine with a short stroke gas piston, separate from the gate frame. When fired, the gases are discharged through holes in the barrel into the gas chamber, where they act on the movable gas piston, which, in turn, causes the bolt frame to roll back.

At the same time, the shutter rotates, provided by its interaction with the bolt frame (the protrusion passes along the diagonal groove), from which the bolt leaves the combat stops and moves back, carried away by the bolt frame. In this case, the spent cartridge case is extracted through the window of the receiver and the cocking spring.

Then, under the influence of a return spring, the bolt frame goes forward, removes the cartridge from the magazine, drives it into the chamber and after that the rotary bolt locks the barrel channel to three combat stops.

The upper part of the receiver is made of aluminum alloy, and the lower part is made of polymer. Interchangeable trunks are attached to the upper half with two transverse bolts. A fuse-translator of firing modes was launched on both sides of the weapon: single shots and a continuous queue.

Models are also available with a cut-off for a queue of three shots. The handle for cocking the shutter can be inserted on both sides of the upper part of the receiver, for this special cuts are made on it. Also on both sides of the duplicated button latch store.

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The plastic butt is telescopic, it can be adjusted in length, for ease of transportation the butt is folded to the side.

On this rifle, you can install a 40 mm grenade launcher or front handle, lights, bipods, as well as any additional sights (optical, collimator, thermal imaging, night vision, laser target designators, etc.).


As already mentioned, the SCAR shooting system has two basic options: light (SCAR-L) and heavy (SCAR-H). The main difference is the ammunition used, since the SCAR-L system is designed for the use of 5.56×45 mm NATO cartridges (any army cartridges, both standard general-purpose M855 and any other cartridges of this caliber – cartridges with armor-piercing bullets, with heavy bullets, increased power and vice versa, reduced for firing with a silencer, cartridges with tracer bullets, etc.).

The SCAR-H system uses a powerful NATO cartridge of 7.62×51 mm caliber in any of its variations as a standard cartridge, and after changing some components (the lower part of the receiver with the magazine receiver, shutter, barrel), it is possible to use other cartridges of the same caliber – 7, 62×39 mm (M43), which shot the Soviet AK47 and AKM.

The use of this cartridge in certain situations will be the golden mean between powerful 7.62×51 and high-speed light bullets of 5.56×45 cartridge. Firing in bursts when using cartridges of 7.62×39 mm will be more controllable than when using 7.62×51 and the bullets will be more stable in flight than bullets of 5.56 mm caliber and will also have greater penetration than 5.56×45.

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Two options (SCAR-L and SCAR-H) can have the following configurations, differing in barrel length:

CQC (Close Quarters Combat – an option for close combat with a short barrel, front handles are often installed on these for stability of the battle bursts).

STD (Standard – a standard version of the barrel length).

SV (Sniper Variant – a long-barrel rifle, sniper modification, can also be used as a light machine gun, it is advisable to mount bipods and optical sights).

To use the long-barrel modifications as light machine guns, there are special high-capacity magazines, which are double disk magazines.

These variants of this weapon system have the same device, as well as working mechanisms, repair and cleaning procedures.

On their own, any fighter with a minimum of tools can change the barrel (interchangeability of parts is 90%). Such a modular system provides the army unit with the most flexible weapons that can be easily changed for any task, from firing automatically in cities, during battles in buildings from a convenient carbine, to firing to suppress a light machine gun and sighting single sniper shots at ranges up to 500- 600 meters. Also, do not forget about the underbarrel grenade launcher.

The FN40GL grenade launcher included in the complex has a caliber of 40 mm, for the SCAR-L and SCAR-H rifles the grenade launcher is not interchangeable, for the 5.56 mm light model it is slightly shorter than for the 7.62 mm heavy model .

This is due to the difference in the dimensions of the weapon, or rather the difference in the width of the receiver of the store, and, accordingly, of the store itself, due to the longer cartridge 7.62×51 in the FN SCAR-H rifles.

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The grenade launcher trigger is a ring that you need to pull yourself to fire. This option allows you to shoot from the grenade launcher with the hand holding the pistol grip of the rifle without changing the position of this hand, which is very convenient.

The trigger mechanism of the grenade launcher is self-cocking, double-acting, the automatic cocking of the striker occurs at the time of reloading by moving the barrel. The grenade launcher works according to the standard scheme with a moving barrel, the rifled barrel.

The reloading occurs by moving the grenade forearm forward, from which the barrel moves forward, opening to receive a new shot and discarding the shot sleeve of the previous shot. The design of the grenade launcher is based on the design of the integrated grenade launcher of the FN 2000 rifle complex model.

In an autonomous version, a module with a telescopic retractable butt, a pistol grip and a Picatinny rail on top, on which any sights and auxiliary devices are mounted, is attached to the grenade launcher.

As a result, we can say that the FN SCAR complex is a universal weapon, with minimal manipulations it can be transformed into any of the main types of small arms.

The grenade launcher of the system is also universal, as described, plus a wide variety of shots of 40 mm caliber for this grenade launcher further expands the scope of capabilities of the weapon. The combat use has already shown that this weapon works for five plus. This is a truly modern effective and versatile army small arms, one of the best examples.

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