JS-103

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Type 103 Automatic Rifle (JS-103)
JS-103 main.png
Common configurations of the baseline JS-103
Typeassault rifle
Place of origin Menghe
Service history
In service2004 to present
Used bysee "Users"
Production history
DesignerInsŏng New Arsenal
Designed1996-2003
ManufacturerChowonsuri 2nd Machine Plant, Taekchŏn
Produced2003 - Present
Variantssee below
Specifications (JS-103 standard model)
Weight3.5 kg without magazine
3.9 kg with 30rnd magazine
Length945 mm (stock extended)
698mm (stock folded)
Barrel length467 mm
Width68 mm
Cartridge5.7x40mm
ActionGas operated, rotating bolt
Rate of fire650 rpm
Muzzle velocity900 m/s
Effective firing range500 m
Maximum firing range800 m (area target)
Feed system10, 30, or 45-round detachable box magazine or 100-round drum magazine
SightsAdjustable iron sights
Side rail for attaching optics

The JS-103 (Formal designation: 103식 자동 소총 / 一〇三式自動小銃, Il-yŏng-sam-sik jadong sochong, "Type 103 automatic rifle;" Short designation 103식, Iryŏngsam-sik, "Type 103") is a gas-operated, selective fire assault rifle developed in Menghe to replace the earlier JS-67. Unlike its predecessor, which was chambered in 7.62x39mm ammunition, it fires a smaller and lighter intermediate round. It has replaced the JS-67 and JS-93 in all active-service units of the Menghean Army, though most reservist units still use the older weapons.

Development

Policy discussions about the procurement of a new assault rifle were already underway in the mid-1990s, but it was only around the turn of the century that the Menghean Army expressed serious interest in the idea. Much of the debate stemmed from conservative-minded officers' concern that lighter cartridges would lack the performance of the then-standard 7.62x39mm round, and that more modern service weapons would lack the reliability of the JS-67 and JS-93.

Combat experience in the Polvokian Civil War finally pushed the Menghean Army to express serious interest in a new service rifle, which would itself be lighter while carrying lighter ammunition. Launched in 2000, the "JS-Sinsegi" (Assault Rifle for the New Century" project called for a weapon with polymer furniture, a three-round burst setting, an optional under-barrel grenade launcher, an improved muzzle brake, and similarity to the JS-93 in layout and maintenance. The cartridge used by the weapon was left undecided, as the Army's own procurement staff had yet to settle their own disagreements about whether to transition to a lighter round.

Five leading prototypes for the "JS Sinsegi" assault rifle, in different cartridges.

The Insŏng New Arsenal, Menghe's leading small-arms producer, responded with two related sets of prototypes chambered in four possible calibers. The first used the same 7.62x39mm round as previous Menghean assault rifles, while the second used the Letnian 5.45×39mm cartridge, reputed for its good wounding effects. In light of the new regime's greater openness to Western powers, the next two prototypes used Western cartridges: 5.56×45mm and 5.7mm Quinn. These prototypes differed in using a straight-insert magazine well, in contrast to the "rock-and-lock" magazine well of the Letnian-patterned and indigenous weapons. They also had milled lower receivers with revised magazine wells, as well as different trigger mechanisms which included three-round-burst capability.

Trials took place throughout 2001 and 2002, though Army evaluators were slow to reach a conclusion. The 5.45mm Letnian round was eliminated due to its poor anti-armor performance, and the 7.62x39mm prototype proved noticeably heavier than its competitors, especially when adding the weight of an 8-magazine combat loadout. Consistent with Galenic testing, the 5.7x40mm round performed noticeably better than the other two intermediate cartridges at long ranges, and exhibited better accuracy than the 7.62x39mm precursor. On the other hand, "old cadre" Army officers viewed the milled lower receivers of the Western-magazine versions as inefficient with regard to weight and production time, noting that they added nearly half a kilogram onto empty weight. Additional debate centered on whether the weapon should have three-round burst capability: combat experience in the Polvokian Civil War suggested that accurate burst fire at long range was valuable in low-intensity combat, but old cadre conservatives saw the new trigger group as unnecessarily complex, and preferred to stick with existing Menghean infantry tactics, which favored close-range assaults using automatic fire. Handling trials also revealed problems with STANAG magazines failing to latch properly when inserted, taking longer to switch, and failing to feed properly after very rough handling, though these issues were likely a result of unfamiliarity on the part of conscript testers rather than inferiority on the part of the weapon itself.

As a response to problems with the 5.7 magazines, the Insŏng New Arsenal drew up a hybrid fifth prototype. It featured a custom-built Menghean magazine which loaded 5.7mm cartridges but used an AN-style lock and release notch on the back rim. The new stamped steel magazines also stood up to rough usage better and were much less likely to suffer feeding problems, at the cost of being heavier. Just as importantly for the procurement conservatives, they could feed into a stamped lower receiver with no burst-fire mechanism. In June of 2003, the Menghean Army finally adopted this modified fifth prototype as the "Type 103 Automatic Short Rifle," or JS-103 in Anglian-language promotional literature, and ordered it into limited production.

Design (JS-103)

File:JS-103 sidebar.png
At the top is a standard JS-103 beneath a JS-67 for comparison. The next five in the list show (i) the stock in the folded position, (ii) a standard optics mount, (iii) a YB-42 under-barrel grenade launcher, (iv) a standard bayonet, and (v) an under-barrel flashlight.

The JS-103 has some resemblance to the original JS-67, and it shares the same general internal layout, allowing soldiers trained in one weapon to easily learn how to disassemble and maintain the other. Its most visible change is the use of high-strength black polymer furniture rather than wood, a measure intended to save weight. The metal parts are also given a protective coating intended to reduce wear, and in general the weapon retains the rugged simplicity of its predecessor. Unlike the JS-67, the JS-103’s stock is hinged, and can swing to the left side and lock into position to reduce the weapon’s length.

Although earlier prototypes included a large muzzle brake with two openings per side, the final JS-103 design used a smaller muzzle brake to reduce the effect of gas deflection to soldiers on either side. This muzzle brake has screw threads to permit the installation of a blank-firing adaptor but in its standard variant it cannot accept suppressors, extra muzzle brakes, or other end-of-barrel attachments. The weapon is unable to fire rifle-grenades, and no rifle grenades for the weapon have been put into service. Instead, the JS-103 relies on under-barrel lugs to allow the mounting of a separate YB-42 42mm grenade launcher. This is aimed using a fold-out sighting bar with angle increments for different ranges.

In place of picatinny rails on top of the weapon, the JS-103 has a single rail on the left side, which can be used to mount a variety of sights on specialized adaptor mounts. It is almost always loaded with 30-round magazines, though it can also accept the 45-round box magazines and 100-round drum magazines designed for the GG-103 (see below).

The JS-103 also has under-muzzle mountings for a new type of bayonet, which is shorter and sturdier than the “sword” bayonet used for the JS-67. This bayonet incorporates a rear hook which can be used as a simple can-and-bottle opener or a wire cutter, when paired with the steel edge of the sheath. It is not reverse-compatible with the bayonet mounting on the JS-67, nor can the JS-67’s bayonet be mounted on the JS-103.

In fully automatic mode, the JS-103 has a cyclic rate of fire of about 600-700 rounds per minute. Combat exercises determined that the "effective" rate of fire in combat is closer to 100 rounds per minute. The standard JS-103 safety switch includes settings for fully automatic fire, three-round bursts, and semi-automatic fire. Its effective range against a running target is usually listed as 500 meters but may be closer to 300 in practice for a conscript soldier using iron sights, and the 800-meter "range against area targets" is apparently no longer incorporated into training, though the iron sights do adjust out to 1000 meters.

Variants

JjS-104

The JjS-104 (104식 짧은 소총, Il-yŏng-sam-sik jjalbŭn sochong, "Type 103 short rifle") is a carbine variant of the JS-103, with a shortened barrel and a lighter stock. Otherwise, it uses the same receiver as the full-size weapon. Because the barrel is shorter, the weapon has a lower muzzle velocity and greater dispersion, reducing the effective range to 400 meters. It is also unable to mount the standard 42mm grenade launcher. In Menghean Army service, the JjS-103 is generally issued to the crews of armored vehicles, who may have to store the weapon in a confined space and quickly carry it out of a hatch when exiting the vehicle. It is 713 mm long with its stock extended, 518 mm long with its stock folded to the left, and weighs 2.7 kilograms without a magazine.

GCh-105

The GCh-105 with drum and box magazines. At the bottom is the GCh-105PCh with BARS mechanism.

The third partner in the original JS-103 triad, the GCh-105 (105식 기관총, Il-yŏng-sam-sik gigwanchong, "Type 105 machine gun") is a light machine gun built in the same style as the GCh-67 before it. It has a longer, heavier chrome-plated barrel, which increases accuracy in automatic fire at range. The new barrel is also more resistant to overheating, but lacks a quick-change mechanism, reducing the sustained rate of fire compared to a dedicated light machine gun. The Menghean Army deemed these sacrifices worthwhile, as the weapon is mainly intended for small Mechanized Infantry squads which have fewer footsoldiers than APC-borne units and can usually rely on the firepower of their IFV.

Save for a few modifications to the return mechanism and recoil spring, the GCh-105 uses the same receiver parts as the JS-103, aiding in training and maintenance. It can also be recognized for its "club-foot" stock and always carries a bipod. The standard-issue GCh-105 is 1.084 meters long with stock extended and weighs 5.03 kilograms empty.

When the GCh-105 was first introduced, the Menghean Army issued it with 75-round drum magazines, though it is also compatible with the standard 30-round magazines issued to other squad members. Field trials and exercises soon revealed problems with the drum magazines, which were known to jam and break easily. Soldiers also complained that the large drums were too bulky when carried in webbing. The Army responded by developing a 60-round, quad-stack casket magazine. This is similar in external dimensions to the 30-round double stack magazine for the JS-103, albeit twice as thick at the base, and after receiving much better reviews from soldiers it has been phased in as the new standard option.

GCh-105PCh

In 2011 the Insŏng New Arsenal unveiled a new variant of the GG-103, designated the GCh-105PCh. Like the JS-103PCh described below, it incorporates a balanced recoil system (BARS), and also widens the gas port and shifts it further back. In combination with the heavy barrel and bipod, this allows for greater accuracy during sustained automatic fire. Army officials initially delayed procurement due to concern that this change would reduce the size of the beaten zone, trading away area-suppression capability for precise fire on individual targets. Nevertheless, after 2015 the Army ordered the GCh-105PCh into large-scale production, apparently with the aim of fully replacing the GCh-105 in Class 4 units.

JS-103PCh

Although it was not part of the original design requirement, Insŏng developed an experimental variant of the JS-103 with a balanced recoil system extending forward over the barrel. The suffix PCh stands for Pyŏnghyŏngchu, or "counterweight," a reference to this recoil balancing feature.

Due to its lengthened barrel and revised muzzle brake, also intended to improve accuracy, the weapon is six centimeters longer than the basic JS-103 and 800 grams heavier. Early trials conducted by Insŏng in 2005 claimed that the weapon "virtually eliminated recoil and muzzle climb, allowing highly accurate automatic and burst fire," but fed suspicion in the procurement agency that the manufacturer was exaggerating the weapon's capabilities in order to win sales. The remaining members of the old establishment also expressed concern that the added moving parts could make the weapon more prone to jamming, a fear which later proved unsubstantiated.

In 2007, the Army ordered a batch of JS-103PCh rifles for Gunchal rear-area patrol units, but did not place any additional orders for several years. A state news agency, quoting mid-level Army news bureaus, suggested that the program had been killed, but in 2012 the Army's Airborne Assault Forces placed large orders for new JS-103PChs with the aim of replacing the JS-103 in all of its combat units. The Marine Infantry followed suit in 2014.

At an October 2016 news conference, however, the Procurement Board of the Menghean Army confirmed that it would place orders for regular Army units "beginning in 2017." This announcement, along with leaked documents about the status of the BSCh-12 IFV program, led to speculation in defense circles that the implementation date for the Class 5 Army Reorganization had been moved ahead from 2025 to 2020.

JS-103DB

Unveiled at a 2008 arms show, the JS-103DB is an independent design project developed by Insŏng in the absence of an Army requirement. It consists of a JS-103 rebuilt in a bullpup configuration, using the original barrel, piston, and receiver with reconfigured furniture. The trigger is connected to the firing sear by a flat steel rod running inside the lower receiver, and the safety is not duplicated. The Menghean Army balked at the weapon, citing its poor ergonomics, but it received some interest from foreign customers, including Idacua, which purchased 1000 examples for its special forces in 2012.

Full list of variants

  • JS-103: Standard assault rifle variant used by the Menghean Army.
  • JS-103 Naean: Special variant for the Internal Security Forces. It is only capable of semi-automatic fire. It is generally issued 10-round magazines, but is capable of accepting 30-round magazines.
  • JjS-104: Carbine variant.
  • GCh-105: Light machine gun variant.
  • TS-106: A dedicated variant for the special forces, based on the JjS-104 but with a built-in suppressor. It has been seen with both 20-round and 30-round magazines.
  • JS-107: Variant of the JS-103 with recoil balancing system.
  • GCh-115: Variant of the GCh-105 with recoil balancing system.
  • JS-103L: Export variant chambered in 7.62x39mm. Capable of accepting AN-47 magazines.
  • JjS-104L: JjS-104 chambered in 7.62x39mm.
  • GCh-105L: GCh-105 chambered in 7.62x39mm.
  • JS-103G: Export variant chambered in 5.56x45mm, using the milled lower receiver and a 3-round burst mechanism. Capable of accepting STANAG magazines.
  • JjS-104G: JjS-104 chambered in 5.56x45mm.
  • GCh-105G: GCh-105 chambered in 5.56x45mm.
  • JS-103Yu: Export variant chambered in 5.45x39mm. Capable of accepting AN-74 magazines.
  • JjS-104Yu: JjS-104 chambered in 5.45x39mm.
  • GCh-105Yu: GCh-105 chambered in 5.45x39mm.
  • JS-107G: 5.56x45mm export version of the JS-107, first showcased in 2011. Also features milled lower receiver with 3-round burst setting.

Users

See also

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