Daewoo K2
same rifle, butt folded

Daewoo K1A1 (shortened version); buttstock in extended position

Daewoo DR-200 (semi-auto civilian version in .223 Remington), without magazine; note the "post-1994 ban" thumbhole non-folding buttstock, required by current USA laws

	Daewoo K2 rifle	Daewoo K1A1 carbine
Caliber	5.56x45mm NATO
Overall length (butt open / folded)	980 / 730 mm	838 / 653 mm
Barrel length	465 mm	263 mm
Weight	3.26 kg less magazine	2.87 kg less magazine
Magazine capacity	30 rounds
Rate of fire	750 rounds per minute	800 rounds per minute
Effective range	500 meters	250 meters

The K1 assault rifle was developed circa 1983 by the South Korean company Daewoo Precision Industries Ltd (a division of the large industrial corporation DAEWOO International Corp.) as a replacement for the license-built M16A1 rifles, used by the South Korean Army during the 1970s. The improved version, Daewoo K2, appeared circa 1987 and replaced the K1 rifle in production and service. At the present time the K2 assault rifle and K1A1 carbine are the general issue shoulder arms with the South Korean Army. Semi-automatic only, export versions of the K2 rifle, known as a Daewoo DR-100 (pre-1994), DR-200 (post-1994, both chambered for .223 Remington cartridge) and DR-300 (post-1994, chambered for Russian 7.62x39mm cartridge), are intended for the civilian and police markets. The earlier K1 semi-automatic versions were exported from Korea as Daewoo MAX-1 and MAX-2 rifles (both in .223 caliber).
The K2 rifles were designed as improved variations of the M16 rifle. While retaining most of the M16 design features, Daewoo designers replaced the direct gas system of the AR-15/M16 rifle with the more common and reliable gas piston system, and made several other improvements, resulting in very good combat weapon.
Technical description.
The Daewoo K2 is a gas operated, selective fire, magazine fed weapon. The K1 rifle and K1A1 carbine differs from the K2 rifle by different gas system, shorter barrel with different muzzle compensator / flash hider (K1A1 carbine only), and different type of buttstock.
The K2 gas system features a long stroke gas piston, located above the barrel. The bolt group is more or less similar in design to the M16 design, with rotating bolt that have 7 lugs and locks directly into the barrel extension. The cocking handle is attached to the right side of the bolt carrier and reciprocates when gun is fired. Some sources, however, stated that the K1 rifle had the gas system similar to the one found in AR-15/M16 rifles, with no separate gas piston and gases being directed straight into the bolt carrier. The return spring with its guide rod is located behind and partially inside the gas piston rod, and, unlike the M16, does not take space in the buttstock, allowing for folding or completely retractable butt to be used.
The receiver is generally similar in design to the M16 rifle, and is made from two halves, upper and lower, machined from the aluminum alloy forgings, and linked by two cross-pins. It must be noted, however, that Daewoo receivers are NOT interchangeable with any AR-15/M16 type receivers.
The trigger unit is fitted with the 4 position safety / fire selector switch, located at the left side of the receiver, above the pistol grip. The switch has positions for Safe, Single shots, 3 rounds bursts and Full auto fire. It must be noted that the 3 rounds burst counter does not reset itself if trigger is released before all 3 rounds are fired.
The feeding is achieved by using M16-type magazines. Both K2 and K1 rifles incorporate a bolt stop device, which holds the bolt open after the last shot from the magazine is fired.
The sighting system consists of the hooded front sight, mounted on the gas block, and the L-shaped dual aperture rear sight, with one small aperture for daylight conditions and another larger aperture for low light conditions. The range adjustments are made by the rotating knob at the right side of the rear sight block. Maximum range setting is 600 meters. K2 also can be fitted with the see-thru scope rail just ahead of the rear sight block.
The K2 rifle is fitted with the side-folding plastic buttstock and plastic furniture. K1A1 carbine has the retractable steel wire buttstock.

K11 dual-caliber air-burst weapon, left side

K11 dual-caliber air-burst weapon, right side
Caliber: 5.56x45mm NATO + 20x30B mm
Action: Gas operated, rotating bolt for 5.56mm and manually operated for 20mm
Overall length: 860 mm
Barrel length: 310 mm (5.56mm); 405 mm (20mm)
Weight: 6.1 kg (with optics and battery but less magazines)
Rate of fire: ?
Magazine capacity: 30 rounds of 5.56mm and 5 rounds of 20mm
The K11 dual-caliber air-burst weapon was first shown to public in 2009, during DSEI military expo, although information on its development was available since about 2006. The K11 (XK11 during early development) weapon is being developed under direction of the Agency for Defense Development of the Republic of Korea. The K11 shows more than passing similarity to the ill-fated American XM-29 OICW weapon, but it appears that K11 has better chances to see the service - it is believed that first unit of South Korean army could receive the K11 weapons in 2010. This is not surprising, considering the fact that Republic of Korea is among world's leading countries in the field of design and production of advanced micro-electronics, and also has an established defense industry and strong motivation for constant upgrade of military equipment.
As of now, the K11 dual-caliber air-burst weapon is proposed for infantry squad support role, multiplying soldiers capabilities to engage enemy personnel in defilade and soft-skinned vehicles and equipment, using 20mm air-burst grenades with pre-programmed fuse and 5.56mm ammunition for short- to medium range direct fire.
K11 dual-caliber air-burst weapon consists of three major units, linked into one weapon. Those are 20mm multi-shot grenade launcher (which serves as a bone to the system), the 5.56mm automatic rifle with firing controls, and an electronic fire control unit.
The grenade launcher is a manually operated, bolt action weapon that is fed from detachable box magazines. It is built in bullpup layout, with aluminum alloy receiver and titanium alloy barrel. The trigger system of the grenade launcher is mechanically linked to the trigger / selector / safety unit of the integral rifle component. The rifle component is more or less conventional, gas operated, rotary bolt selective-fire weapon which uses M16-type magazines. Its layout is more or less similar to US-made M16 or Korean-made K2 rifles. The trigger unit is a common part between grenade launcher and rifle components, with single safety / fire selector lever providing fire from grenade launcher (single shots) or rifle (single shots or 3-round bursts). The third component is an electronic fire control unit, which includes laser rangefinder, environmental sensors, ballistic computer, and day (optical) and night (IR) sighting channels. The ballistic computer output is fed to the electronic aiming reticle (providing visible point of aim pre-set for proper range) and to the fuse-programming unit in the grenade launcher, which sets the 20mm grenade to explode at specified range, above or to the side of the target, to provide maximum kill effect from explosive fragmenting warhead. At the present time, two types of 20mm ammunition are specified for K11 grenade launcher - the K167 HE air-burst grenade and K168 TP target practice grenade. Rifle component can use any NATO-standard 5.56mm ammunition.

Stg.45(M) - German predecessor to CETME rifles, made at the Mauser Werke in 1945

Early CETME assault rifle prototype chambered for experimental 7.92x40mm cartridge

CETME modelo A assault rifle, chambered for 7.62x51mm reduced load cartridge

CETME modelo B / mod. 58 with 30 rounds magazine

CETME modelo C rifle (semi-automatic only "Sporter" version shown)

data for CETME mod. B / Mod. 58 rifle
Caliber: 7.62x51 mm reduced power load; also 7.62x51mm NATO
Action: delayed blowback
Overall length: 1015 mm
Barrel length: 450 mm
Weight: 4.4 kg
Rate of fire: 550 - 600 rounds per minute
Magazine capacity: 20 or 30 rounds

The Spanish state company CETME (Centro de Estudios Tecnicos de Materiales Especiales - Special Materials Technical Studies Center, now known as Empresa National Santa Barbara) was founded in 1949 to develop various small arms for Spanish army. At about the same time it employed the German arms designer Ludwig Vorgrimler, who worked for the famous Mauser Werke in Germany before and during the World War 2. The Vorgrimler was the designer of the experimental German assault rifle, known as "Gerat 06" or Stg.45(M). This rifle was not manufactured in any quantities, but its design served as a basis for further development at the CETME, and more important, at the another German company, Heckler & Koch, which obtained a license for the Vorgrimler / CETME rifle design circa 1957. This deal later resulted in the famous family of the H&K weapons, like the G3 and HK33 assault rifles, HK21 and HK23 machine guns, MP5 submachine guns and numerous other small arms that achieved a worldwide popularity. All those weapons are built using the delayed blowback system of operation, designed by Vorgrimler and his men at the Mauser in 1945 and refined by CETME.
The initial assault rifle development at the CETME was conducted around proprietary intermediate cartridge, known as 7.92x40mm CETME. This cartridge featured a long and streamlined bullet, made from aluminum. The overall design was found adequate, but cartridge was rejected in favor of the 7.62x51mm round with lighter bullet and a reduced powder charge. Improved rifle entered serial production in 1956 and was adopted by the Spanish army in 1957. In 1958 CETME introduced a slightly improved design, known as Modelo B or Model 58. This rifle was intended to fire 7.62x51mm reduced loads but also could fire the standard 7.62mm NATO, if the bolt group and the return spring are replaced with the appropriate set of parts. In 1964, CETME introduced the Modelo C, which also was adopted by Spanish Army, Navy and Air Force. This rifle was intended to fire only standard, full power 7.62x51mm NATO ammunition. Its key improvements were 4-position diopter sights (instead of the earlier leaf type open sights), wooden handguards instead of earlier steel ones, bipod was made as a separate part and, most important, the chamber was fluted to improve extraction and avoid torn rims and cartridge case failures in harsh environment conditions. Production of the modelo C rifle was ceased in 1976, and in 1980s it had been gradually replaced by its 5.56mm derivative, CETME Modelo L assault rifle.
All 7.62mm CETME rifles are built around Vorgrimlers' roller delayed blowback system. This system employs a two parts bolt with two rollers. The front bolt part (bolt head) is relatively light and has a bolt face with extractor on it. It also has a hollow cavity at the rear, in which an inclined forward end of the rear part of the bolt (bolt body) is inserted. The system features two rollers, inserted from the sides into the bolt head and rested on the inclined forward end of the bolt body (see this diagram; it will pop up in the new window). When gun is fired, the pressure began to move the cartridge back against the bolt face. The rollers, which are extended into the recesses in the barrel extension, began to move inward into the bolt head, due to inclined shape of the recesses. This movement translates into the faster rearward movement of the heavier bolt body, so, at the initial moments of shot, when pressure in the chamber is still high, bolt face moves relatively slow. When pressure drops to a reasonable level, rollers disengage the barrel extension completely and from this moment on the bolt head and the bolt body move backward at the same speed, extracting and ejecting spent case and chambering a fresh cartridge on the way back. All CETME rifles are firing from the closed bolt. The trigger mechanism is hammer fired, and in military versions is capable in semi-automatic and fully automatic modes of fire. On the early models the safety / fire mode selector switch was located above the trigger at the right side of the gun. From the model C the safety / selector switch was relocated to the left side of the gun. The receiver is made from steel sheet stampings, as well as the trigger group housing, which is hinged to the receiver just behind the magazine housing. Early models (prior to Modelo C) were issued with integral folding metallic bipods and open leaf-type rear sights. The Modelo C rifles were issued with wooden handguards and a separate detachable bipods. The rear sights were replaced by the 4 positions diopter sights, marked for 100 - 400 meters range. All rifles featured a wooden buttstock and a folding carrying handle above the receiver. The flash hider of the Modelo C rifles was shaped to accept and launch NATO-standard rifle grenades. Most rifles were issued with magazines of 20 rounds capacity and made of steel, but 30 rounds magazines also were available.

CETME Mod. L assault rifle
Caliber: 5.56x45 mm NATO (.223 rem)
Action: Delayed blowback
Overall length: 925 mm (860/665 mm mod. LC)
Barrel length: 400 mm (320 mm mod. LC)
Weigth: 3.4 kg empty (3.22 kg Mod. LC)
Rate of fire: 600 - 750 rounds per minute
Magazine capacity: 12 or 30 rounds

The Mod. L rifle had been developed by Spanish CETME company (now Santa Barbara SA) as a further derivative of the previous Mod. 58 ad Mod. B rifles. These rifles, in turn, have their roots in WW2 German assault rifle Stg.45, developed by Mauser. After the WW2, some Mauser men moved to the Spain and started to work for CETME, where they developed the Mod. B battle rifle, chambered for 7.62mm NATO cartridge. This rifle later was licensed by Heckler&Koch and beбame the famous G3, but CETME also continued the development. In the mid-1960s men at CETME began to work at smaller-caliber version of the basic rifle, initially called Mod. E. Development was completed in 1980, when first prototype of the Mod. L, chambered for 5.56mm cartridge appeared. Production of the Assault Rifle Mod. L and carbine Mod. LC began in 1984, and it was adopted by Spanish army. In 1999 this rifle was declared obsolete by adoption of the H&K G36E assault rifle.
Like the previus models, CETME Mod. L is a delayed blowback operated, selective fire assault rifle. It has two-piece bolt with two rollers, which are used to accelerate bolt body and to slow bolt head and to hold the cartridge case in chamber until the pressure will drop. The chamber walls are fluted to help the extraction. Overall design is somewhat similar to H&K 33 rifles, but Mod. L is easily distinguishable by larger triggerguard and different (from HK designs) plastic pistol grip and handguards. Sights on Mod. L also are different from HK pattern and rear sight is a simple flip-up "L" shaped leaf with two apertures for 200 and 400 meters. Magazine port also is different from HK pattern and is designed to acceptt M16-type magazines. Carbine Mod. LC differs from the Mod. L by having shorter barrel and telescoping metallic buttstock.

Bofors AK5 - basic version

Bofors AK5B - scoped designated marksmen rifle

Bofors AK5 with M203 grenade launcher

Bofors AK5D - shortened version with Picatinny rail
Caliber: 5.56x45mm NATO
Action: Gas operated, rotating bolt
Length: 1008 mm (Stock Extended), 753 mm (Stock Retracted)
Barrel Length: 450 mm
Weight: 3.90 kg
Magazine: 30 rounds box
Rate Of Fire: 650 rounds per minute
Sweden adopted its first 7.62 mm assault rifle in 1963, as the AK-4. It was a license-built version of the Heckler & Koch G3  rifle, which served well until the adoption of the 5.56 mm ammunition in 1984. After extensive trials, which included designs like the Israeli Galil (made under license by FFV of Sweden), the German HK33, the American M16A1, the Swiss SIG SG-540 and some other designs, the Swedish army finally selected the Belgian FN FNC as its next weapon. The basic FN FNC rifle was modified to suit Swedish requirements, the most notable changes being the omission of the 3-round burst mode of fire, an enlarged trigger guard, a thicker forend and improved, corrosion-resistant finish on all metallic parts. First deliveries were made from FN circa 1986, and domestic rifles began to enter service a year later, made at Bofors' Karl Gustaf factories. The modified FNC rifle, adopted as the AK-5, is now in service with Swedish armed forces.
The AK5 assault rifle is essentially similar to the Belgian FN FNC rifle, except for several modifications. First, the AK5 has no provision for the 3-round burst mode, and will fire only single shots or full auto. Second, the buttstock and handguards are made longer and more suitable for winter conditions, and the charging handle enlarged for better grip when using arctic mittens. Special surface treatment is used for better protection against the elements. The AK5 is manufactured in several modifications, including the basic AK5; the AK5B with 4X telescopic sight (British SUSAT L9A1) and cheek-pad on buttstock, which is issued as a squad-level marksmen rifle; AK5C with Picatinny rail and no open sights; AK5D with the shortened barrel, and integral carrying handle with built-in telescope sight, intended for Commando units and paratroopers; and a grenade-launching version, fitted with American M203 40mm grenade launcher, which is used mostly by Rangers and amphibious forces.

the Interdynamics MKS assault rifle (top, with buttstock unfolded) and MKS carbine (bottom, with buttstock folded)

	MKS rifle	MKS carbine
Caliber	5.56x45 mm
Action	Gas operated, rotating bolt
Overall length (butt open / folded)	868 / 634 mm	751 / 517 mm
Barrel length	467 mm	350 mm
Weight	2,75 kg	2,36 kg
Rate of fire	750 - 1100 rounds per minute
Magazine capacity	30 rounds

The Interdynamics AB company of Sweden attempted to enter an assault rifle market with its MKS rifle in mid-1970s. The Interdynamics MKS assault rifle was more or less conventional in respect to materials and technologies, but layout was not conventional, with box magazine serving as a pistol grip. This layout resulted in shorter overall length when compared to conventional rifles with the same barrel lengths, but seriously compromised ergonomics. Because the standard 5.56mm magazine is significantly deeper 9front to back) than a typical pistol grip, the firing hand's hold and a trigger reach were far from being comfortable. The MKS rifles never were made in any quantities and deserved its place in firearm history more as a curiosity than anything else.
The Interdynamics MKS assault rifle was a gas operated selective fired weapon with rotating barrel locking. Gas system featured a gas regulator. The receiver was made from stamped sheet steel, magazine housing served as a pistol grip. The skeletonized buttstock folded to the right side to save the space. The L-shaped flip-up rear sight has two range settings, for 250 and 400 meters. Carbine version of MKS rifle featured shorter barrel, otherwise being similar to rifle version.

Interdynamics MKR assault rifle

schematic drawing of the 4.5 mm rimfire cartridge for Interdynamics MKR assault rifle
Caliber: 4.5x26 mm Rimfire (special ammunition)
Action: blowback
Overall length: 840 mm
Barrel length: 600 mm
Weight: 3.0 kg less magazine
Rate of fire: no data
Magazine capacity: 50 rounds
The Interdynamics MKR assault rifle was another unsuccessful and unconventional design of the Swedish company Interdynamics AB. Interdynamics MKR assault rifle appeared during 1980s on the top of the "micro-caliber" craze. The idea behind micro-caliber (less than 5 millimeters / .20 inch) ammunition was to achieve high velocity, flat trajectory and good penetration in automatic weapon, and with low recoil. The Interdynamics cartridge was based on .22 Winchester Magnum Rimfire cartridge case, with curved taper and 4.5mm / .177" caliber pointed bullet, made of solid brass. Lightweight bullet (1.58 g / ~24.4 grain) achieved a muzzle velocity of about 1000 m/s (3270 fps). The effectiveness of this bullet was claimed to be on par with 5.56x45mm bullet at the ranges up to 300 meters. Unsurprisingly, the stopping power of such tiny bullet was questionable at its best, and use of rimmed, rimfire ammunition obviously compromised the reliability of the rifle. As a result, Interdynamics MKR assault rifle remained only in prototype stage.
Because of the relatively low power of this ammunition, the MKR gun was made using simple blowback system. Rimmed ammunition was fed from semi-circular magazines, located behind the pistol grip, so the overall layout can be classified as bullpup. Ambidextrous charging handle was located at the top of the plastic receiver. Carbine version of the MKR rifle was similar in design, but had shorter barrel.