Thursday, November 29, 2007

Negev machine gun (Israel)

Negev machine gun, in standard configuration and with 200-round belt container clipped to the magazine housing

Negev machine gun, with short "Commando" barrel, forward assault grip, red-dot sight and 150-round ammunition container

Negev machine gun, with short "Commando" barrel, forward assault grip, laser aiming module and 150-round ammunition container

Negev machine gun with Commando barrel, removed bipod and folded butt; note that rear sight is replaced by Picatinny rail

Negev machine gun with Commando barrel and Galil-type box magazine

Negev StandardNegev Commando
Caliber5,56x45 NATO
Weight7,4 kg7,0 kg
Overall length1020 / 780 mm890 / 680 mm
Barrel length460 mm330 mm
Rate of fire850 - 1150 rounds per minute
Feed systemBelt or box magazine, 30 or 35 rounds

During late eighties IDF requested a development of the 5,56mm light machine gun which could complement reliable, but overly heavy 7,62mm FN MAG machine guns for foot soldiers. The goal was to design a tactical equivalent of the FN Minimi light machine gun, which was tested by IDF but for some reasons was not adopted. First prototypes of the new LMG, developed by Israeli Military Industries Company (now a privately-owned Israeli Weapons Inc) were issued to elite IDF Givati brigade in limited numbers for field testing in 1993. Those early weapons developed a lot of problems with feed reliability and high sensitivity to sand and dust, and further development took about three more years. Starting circa 1996 IMI began to deliver Negev machine guns in limited numbers, and by about 2002 it became more or less a standard issue LMG across the IDF. Negev is favored by Israeli soldiers because it is much lighter and maneuverable than venerable FN MAG, and can be easily manned by single soldier. On the other hand, it is more sensitive to sand and dust that the MAG, and requires more care and cleaning; it also lacks the range and punch of the true GPMG, therefore both 7,62mm MAG and 5,56mm Negev continue to serve in IDF side to side, which obviously is most logical solution.

Negev is a gas-operated, air-cooled light machine gun. It features quick-detachable barrels, with two barrel sizes available – Standard (long) and Commando (short).
Negev machine gun utilizes long-stroke gas piston system located below the barrel. Gas system is fitted with three-position gas regulator, with first (minimum) position used to fire when fed from magazines, second when firing from belts in normal conditions and third – when firing belts under adverse conditions. The gas regulator setting also affects the cyclic rate of fire (position #1 – lowest rate, #3 – highest). The gas piston is attached to the bolt group by dual operating rods, running at either side of receiver, to provide necessary clearance for centrally mounted magazine housing. Barrel locking is achieved by rotating the bolt with four massive radial lugs which engages the cuts in the breech of the barrel.
Firing is from open bolt, and gun provides selective fire capability through three-position manual safety-fire selector, located on the left side of the pistol grip.
Negev machine gun features dual feed system, so it can alternatively use standard disintegrating belts or detachable box magazines. Belt feed unit is installed on the top of receiver, with belt feeding direction from left to right. Belt feed is operated by the side-mounted swinging lever, which is operated by cam track cut in the side of the bolt carrier (system somewhat similar to that used in post-WW2 Czechoslovak machine guns). Magazine housing is located below the receiver, with magazine being inserted vertically up. Ejection window for empty cases is at the right side of receiver, just below the empty link ejection window. By default, magazine housing will accept proprietary box magazines originally designed for 5,56mm Galil assault rifle, with 35-round capacity. An adapter can be installed in magazine housing to use STANAG-compatible (M16-type) 30-round magazines. Belts are usually fed from semi-rigid “assault pouches” with 150- or 200-round capacity. These pouches are clipped to machine gun below the receiver, using special projection at the top which is inserted into magazine housing and locked there using magazine catch. Early pouches were of circular (drum) shape, but later these were replaced with more rigid and reliable pouches of semi-circular shape. When not in use, magazine housing is protected by spring-loaded dust-covers.
Standard furniture includes polymer pistol grip, polymer handguard, and a side-folding Galil-type skeletonized buttstock. A lightweight detachable folding bipod is attached to the gas tube. It is interesting to note that when fitted with short (Commando) barrel and box magazine, and with bipod removed, Negev represents a formidable assault rifle, although it is somewhat heavy by rifle standards. It can be used as an effective CQB weapon, providing high maneuverability in confined spaces, with added benefit of serious firepower, thanks to its relatively heavy and quick-changeable barrel.

Type 64 assault rifle (Japan)

Type 64 assault rifle

Caliber: 7,62x51 mm
Action: Gas operated, tilting bolt
Overall length: 990 mm
Barrel length: 450 mm
Weight: 4,3 kg less magazine
Rate of fire: 450-500 rounds per minute
Magazine capacity: 20 rounds

In 1957 the Japan Self-Defense Forces (JSDF) began the search for a new automatic infantry rifle. Being heavily biased to the US in its military trends, Japan probably had no option in ammunition other than the newest US creation, the 7.62x51 NATO cartridge. However, the JSDF felt that it was too powerful, especially for the smaller and lighter Japanese soldiers. Japanese experts accordingly developed a reduced loading, similar in all dimensions to the standard 7.62 mm NATO but with a lighter bullet and a smaller powder charge that generated muzzle velocities of about 715 meters per second instead of the 'NATO original' 810 meters per second. The Howa Machinery Co developed the rifle for new cartridge, working closely with the JSDF. In 1964, the 7.62 mm prototype rifle R6E was adopted for JSDF service as the Type 64 rifle. Howa produced it exclusively for the JSDF until about 1988. Since 1990 the Type 64 rifle has been gradually phased out of service in favor of the 5.56 mm Type 89 rifles. Type 64 rifle was never exported from Japan.

The Type 64 rifle is a gas operated, selective fired weapon. The gas and bolt system were most probably inspired either by the Belgian FN FAL or by Soviet Tokarev SVT-40 rifles. The Type 64 has a short-stroke gas piston located above the barrel and fitted with manual gas regulator. The barrel is fitted with a massive muzzle brake. The bolt is locked by tipping its rear end down into recess in the receiver floor. The charging handle is located above the bolt carrier and is readily accessible by either hand. The safety switch / fire mode selector is located on the right side of the receiver, above the trigger guard.
The striker-fired trigger unit is of original design and features a patented fire-rate reducer, which produces a controllable rate of fire of about 450 – 500 shots per minute. Type 64 rifles are fitted with solid wooden buttstocks and hinged steel buttplates, lightweight folding bipods, and muzzle brakes which also serve as rifle grenade launchers. The open sights are mounted on folding posts, and the rear sight has two range settings, for 200 and 400 meters.
The reduced load cartridges and reduced rate of fire arguably make these and the original Spanish CETME guns the only true assault rifles in 7.62x51 caliber, as they are the only ones, which stand any chance of being controllable in fully-automatic fire.

Tavor TAR-21 assault rifle (Israel)

Tavor TAR-21 assault rifle (standard version)

Tavor TAR-21 assault rifle (standard version), fitted with 40mm M203 grenade launcher and grenade launching sight

Tavor CTAR 21 assault rifle (compact version)

Tavor MTAR 21 assault rifle (micro version)

Tavor STAR 21 (designated marksman) rifle

Civilian (semi-automatic only) version of the Tavor. Note the different shape of the butt, handguard and the trigger guard, basically similar to that of the Micro-Tavor (civilian versions with oversized trigger guard also manufactured).

Tavor TAR-21 partially disassembled

TAR 21TAR C21 / CTAR 21TAR M21 / MTAR 21
Caliber:5,56x45 NATO
ActionGas operated, rotating bolt
Overall length720 mm640 mm590 mm
Barrel length460 mm380 mm330 mm
Weight3,27 kg empty3,18 kg empty2,95 kg empty
Magazine capacity30 rounds
Rate of fire750 - 900 rounds per minute750 - 900 rounds per minute750 - 900 rounds per minute

The development of the new assault rifle, that should eventually replace in service the ageing M16A1, CAR-15 and IMI Galil assault rifles, began in Israel in the 1991. The new rifle was developed by the Israel Military Industries (IMI, now privatized as IWI - Israeli Weapons Industries Ltd) company, in close cooperation with the Israeli Defense Forces (IDF). This new rifle received the name of "Tavor" and the designation of TAR-21 (Tavor Assault Rifle, for 21st century). The new rifle first appeared on public in the 1998, and it had been tested by the IDF during 1999-2002. Initial issue of Tavor rifles to IDF showed some teething problems, but by now the Tavor is already in widespread use by IDF, and it seems that many earlier problems are worked out. It is also in limited use with Special Operation forces of India and Georgia.

In general, the TAR-21 represents the mainstream of the present assault rifle developments. It shares all the "modern" features, already tried and proved successful by previous designs, like the bullpup layout, polymer housing, optical sights as a prime sighting equipment, modular design with several different configurations (from very short submachine gun and up to standard assault rifle and a para-sniper accurized rifle with heavy barrel). So far it seen not much real action, and it is hard to judge if it is really a success, and only time will show that.

The IWI also developed and manufactures a civilian, semi-automatic only version of the Tavor rifle, which looks much like the Tavor Micro rifle but with longer barrel. This version has already been exported to several European countries and Canada.

The Tavor TAR-21 is a gas operated, selective fire, magazine fed assault rifle of bullpup configuration. It is available in several configurations, which differ in the barrel lengths and accessories. The basic configuration is the TAR-21 assault rifle with the 460mm (18.1 in) barrel. Next are the compact assault rifle, called CTAR-21, with the barrel 380 mm (15 in) long, and the micro assault rifle, with the barrel of only 330 mm (13 in) long, called MTAR-21. The latter rifle also featured a redesigned front part of the housing, with charging handle placed further back on receiver, for a more comfortable hold of the short weapon. Micro-Tavor also can be converted to 9mm pistol ammunition (9x19) with installation of the caliber conversion kit, which includes a new barrel, bolt group and a magazine adapter.
TAR-21 utilizes a now-common long piston stroke, rotating bolt action, with the gas piston rigidly attached to the bolt carrier. Gas cylinder is located above the barrel and is completely enclosed by the gun housing. The rotating bolt is similar to one found in the M16 rifle and has seven lugs. The ejection ports are made on both sides of the weapon, and the right or the left side ejection can be selected by installing the bolt with the ejector mounted on the right or on the left, respectively (and, of cause, this change requires the gun to be partially disassembled). The bolt carrier rides on the single guide rod, with the return spring unit located above it, behind and inside the hollow gas piston rod. The charging handle is located at the front left side of the gun and does not reciprocate when gun is fired. The charging handle slots are cut on the both sides of the gun housing, so it can be installed on either side of the weapon, as required. The trigger unit is more or less conventional, with the ambidextrous fire mode selector / safety switch located above the pistol grip.
The TAR-21 has no separate receiver. Instead, all parts are mounted within the high impact-resistant plastic housing, reinforced with steel inserts where appropriate. The access to all the internal parts is controlled by the hinged buttplate, which can be swung down for internal inspection and disassembly.
Early production TAR-21 rifles had no open sights, but this has been fixed with introduction of the folded front and rear sights on current production models. Tavor rifles are fitted with the standard Picatinny-type accessory rail on the top of the gun. Early guns had Israeli-made ITL MARS as standard sight, which is a complicated and expensive reflex-type sight with the built-in laser pointer. For the night time operations the MARS could be complemented with the ITL Mini N/SEAS compact night vision device. Current manufacture Tavor rifles (except for Sniper version) are usually fitted with less expensive Meprolight red-dot sight. Sniper varsions usually are fitted with Trijicon ACOG optical sight with 4X magnification.
The TAR-21 utilizes the STANAG-compliant, M16 type magazines, with standard capacity of 30 rounds.
TAR-21 in its basic configuration can be fitted with 40mm M203 underbarrel grenade launcher.

Daewoo K7 submachine gun (South Korea)

Daewoo K7 submachine gun

Caliber 9x19mm Luger / Parabellum
Weight 4 kg
Length (stock closed/open) 620 / 800 mm
Barrel length n/a
Rate of fire ~1100 rounds per minute
Magazine capacity 30 rounds
Effective range ~100 meters

The K7 submachine gun was developed by Daewoo Precision Industries Ltd Co, a subsidiary to the large DAEWOO Corporation. Daewoo K7 was developed to provide less expensive alternative to German-made HK MP5SD submachine guns, used by South Korean Special Forces. To achieve minimal costs and controls compatibility with other small arms in service with South Korean armed forces, K7 utilizes as many parts from Daewoo-made K1A and K2 assault rifles as possible. Daewoo K7 submachine gun is used by Special Forces of the South Korea and Indonesia.

Daewoo K7 submachine gun is blowback-operated, selective fired submachine gun. It fires from closed bolt, and employs hammer / fire control unit of the K1A assault carbine, borrowed along with aluminum alloy lower receiver. K7 is fitted with bolt hold-open device that holds the bolt open when last round from magazine is fired. The upper receiver is a modified K2 part, with omitted gas system. Telescoping buttstock is also borrowed from K1A carbine. Large magazine well has a special plug installed to accomodate shorter 9mm magazines. The most important feature of the K7 is its integral silencer, which is "wrapped" around the barrel and is said to reduce the sound signature down to about 120 dB.

M/44 Tikkakoski submachine gun (Finland)

M44 Tikkakoski submachine gun with 20-round box magazine

M44 Tikkakoski submachine gun with 71-round drum magazine originally designed for Suomi SMG

Caliber 9x19mm Luger / Parabellum
Weight 2,9 kg empty
Length (stock closed/open) 620 / 830 mm
Barrel length 250 mm
Rate of fire 650 rounds per minute
Magazine capacity 20 or 36 rounds box or 71 rounds drum
Effective range 150-200 meters

This submachine gun was developed during 1943-44 at Tikkakoski OY, Finnish arms-making company, as a less expensive alternative to excellent but overly costly Suomi submachine gun. This weapon in fact was a reverse-engineered copy of Soviet Sudaev PPS-43 submachine gun, adapted to 9x19 ammunition and used Suomi submachine gun magazines. Significatn numbers of M/44 submachine guns were manufactured at Tikkakoski factory during 1944 and 45, and these guns sreved with Finnish army for several decates after the war. It must be noted that the chief designer of M44, someone Willi Daughs, has left Finland soon after the war, and during early 1950s landed in Spain, along with manufacturing documentation for M44. There he managed to find manufacturing facilities, and a copy of M44 was produced in Spain as Dux M53. Small numbers of 9mm Dux M53 submachine guns were subsequently sold to West German Border Guard (Bundesgrenzshutz).

Tikkakosky KP M44 submachine gun is blowback operated, full automatic only weapon. It fires from open bolt. receiver and barrel jacket are made from single piece of sheet steel, cut, bent and welded to shape. Trigger unit is of simple design, copied from Sudaev PPS-43>, with similar sliding manual safety, located in front of trigger guard. The magazine housing is designed to accept all types of magazines, originally developed for Suomi submachine gun, including 20- and 50-round box magazines and 40- and 71-round drum magazines. During ealry fifties M44 submachine guns were slightly modified so it was possible to use new and highly reliable 36-round box magazines from Swedish M45 Carl Gustaf submachine guns (compatibility with older Suomi magazines was retained). Standard sights were of open type, with protetcetd front and L-shaped flip-up rear, marked for 100- and 200-meters range. Metallic butt was of top-folding design.

Jati-Matic submachine gun / GG-95 PDW (Finland)

Jati-matic submachine gun

Diagram from US patent, issued to Jali Timari for design of the Jati-Matic SMG

Caliber: 9x19mm Luger/Parabellum
Weight: 1.65 kg empty
Length: 400 mm
Barrel lenght:
Rate of fire: 650 round per minute

Magazine capacity: 20 or 40 rounds

Jati-Matic submachine gun was designed by Jali Timari and manufactured at Tampeeren Asepaja Oy, Finland, in 1980 - 1987. In 1995 the Jati-Matic briefly appeared again, under the name of GG-95 PDW from finnish company Oy Golden Gun Ltd.

Jati-Matic is a blowback operated, select-fire submachine gun. The bolt recoils up an inclined plane at angle to the barrel, giving an element of braking to the bolt, and also resisting the upward movement of the barrel during the fire. The pistol grip is located higher than on many other SMGs, giving the better control over the recoil. Jati-Matic has no buttstock and has folding forward grip, which also acts as a cocking handle when opened. When folded, front grip also provides an element of mechanical safety, blocking the bolt. The receiver is made from pressed steel with hinged top cover. The selection of the fire mode (single or full auto) can be done with different trigger pulls - short pull produced single shots, long pull - full auto fire.

Suomi submachine gun (Finland)

Suomi M/26 submachine gun, caliber 7,65x22 Parabellum

Suomi M/31 submachine gun with 71-round drum magazine, standard version

Suomi M/32 "tank" or "pillbox" submachine gun with 50-round 4-row magazine, no butt and special barrel jacket

Suomi M 37-39 submachine gun with short barrel, produced under license in Sweden by Husqvarna Vapenfabrik (original M37 weapons were chambered for 9x20 Browning Long ammunition, modified M37-39 - for 9x19 Luger ammunition).

Images from US patent issued to Aimo Lahti for basic design of Suomi submachine gun

Patent diagrams explaining (left to right) 40- and 71-round drums designed by Lahti and 50-round box magazine designed by Schillstrom

Caliber: 9x19mm Luger/Para
Weight: 4.6 kg empty, 7,03 kg with loaded 71-round drum
Length: 870 mm
Barrel length: 314 mm
Rate of fire: 900 rounds per minute
Magazine capacity: 20, 36 or 50-round box magazines and 40- or 71-round drum magazines
Effective range: 200 meters

The Suomi ("Finland") submachine gun was developed by Finnish arms designer Aimo Lachti in 1920-1930 period. First prototype was built by 1922, and by 1926 Lahti produced a working weapon, chambered for then-standard Finnish army's 7,65x22 Luger / Parabellum ammunition. Definitive version of the Suomi submachine gun was adopted by Finnish Army in 1931 as Suomi-KP Model 1931, or simply KP-31 (KP stands for Konepistooli - Automatic Pistol in Finnish language). Suomi submachine gun was manufactured by Finnish company Tikkakoski Oy, and licensed to Denmark (Madsen), Sweden (Husqwarna) and Switzerland (Hispano Suiza). Used mostly by Finnish and Sweden armies, it was also widely exported into Baltic countries, some European and South American countries. Suomi was used with great success during Winter War of 1940 against Soviet Union, when, wisely used, this SMG showed to the world the importance of the submachine guns to the modern warfare. Manufacture of the Suomi was ceased in Finland in 1944, but it was used well until the 1990s, when finally rendered obsolete and replaced in Army by assault rifles.

Suomi submachine gun is a blowback operated, selective fire weapon. It fires from the open bolt, and used so called "differential locking" or "advanced primer ignition" principle, when fixed firing pin ignites the primer BEFORE the bolt stops on its way forward into the battery, so the bolt momentum of inertia is used to lock the chamber during the initial phase of shot, when pressure in the chamber is high. The bolt and receiver were machined from high quality steel and bolt was fitted to the receiver almost airtight. The rear cover of the receiver was screwed on to it also almost hermetically. This was necessary to achieve a fire rate reduction by using a simple vacuum valve in the receiver cover - when bolt moved back, the valve let the air out easily from the space behind the bolt. When bolt started to move forward, the valve closed itself, so difference of air pressures behind the bolt and in atmosphere slowed the bolt on its way forward into the battery.
The charging handle was somewhat similar in appearance to one found on bolt action rifles; it is located behind and below the receiver, and does not move when gun was fired. The safety - fire selector is located at the front of triggerguard, and gun could be fired in semi-auto or in full-auto
Another interesting feature was the quick-detachable barrel and barrel jacket. This feature, more adequate to machine guns, was a welcome during intensive fire-fights, when many hundreds of shots were fired in fully automatic mode. Sometimes the barrel was also fitted with machined muzzle brake / compensator.
Suomi was fed from box or drum magazines. Box magazines were conventional staggered-column ones for 20 rounds or twin-staggered-column magazines for 50 rounds each (also known as "Coffin magazines" due to their shape, these could be described as two staggered-column magazines clipped together and having common cartridge exit). Drum magazines held 40 (rarely encountered early versions) or 71 rounds and later inspired Russians to adopt drum magazines for their PPD and PPSch SMGs. In mid-1950s Finnish army also adopted 36-round magazine, designed in Sweden for M/45 Carl Gustaf submachine gun, and Suomi submachine guns were slightly modified to accept those magazines.

In general, the Suomi KP-31 was a highly effective, reliable and accurate gun, but too expensive to manufacture.

Sunday, November 25, 2007

SVU and SVU-AS (OTs-03AS) sniper rifle (Russia)

Basic SVU (OTs-03) rifle without telescope and with open sights raised to working position

SVU-AS (OTs-03AS) rifle with 4X PSO-1 telescope sight and camo paint; bipod is folded

SVU-AS rifle with bipod extended

Caliber: Russian 7.62x54mm Rimmed
Operation: gas-operated, rotating bolt, semi-automatic (SVU) or select-fire (SVU-AS)
Capacity: 10 round detachable box magazine
Weight: 4,4 (SVU) kg with empty magazine and telescope sight; 5,5 kg (SVU-AS with empty magazine, telescope sight and bipod)
Length: 900 mm
Barrel Length: 520 mm
Rate of Fire: 650 rounds per minute (for SVU-AS only)

The SVU project (Snaiperskaya Vintovka Ukorochennaya - shortened sniper rifle) traces its roots back to 1970s, when it was decided to develop a compact sniper rifle for Soviet airborne (VDV) troops. Such rifle was designed using standard Dragunov SVD action converted to bullpup layout. Back then this project never went past development stage, but in around 1991 it was resurrected in Tula and offered to Russian Internal Affairs Ministry (MVD) as a possible weapon for urban operations. At that time MVD accepted the offer, but requested the rifle to be converted from semi-automatic to selective fired version (probably inspired by German HK G8 "police automatic rifle"). Such conversion was developed by TSKIB SOO (Central Sporting and Hunting Arms Design Bureau in Tula). It was initially known as OTs-03 in semi-automatic version and as OTs-03A and OTs-03AS in selective fired versions (SVU, SVU-A and SVU-AS respectively). Since mid-nineties this rifle was produced in Tula and issued in limited numbers to various law enforcement organizations across the Russia.
There are no firm data on accuracy of SVU rifle, but on short- to medium ranges it is believed to be on par with standard Dragunov SVD rifles.

The basic action of the SVU-AS rifle is inherited from Dragunov SVD sniper rifle - it is a gas operated, rotating bolt design with short-stroke gas piston. The trigger unit is modified with long connect bar, which links forward-mounted trigger with sear back in receiver. In SVU-AS, trigger unit is further modified with introduction of the full-automatic mode of fire. Selection of the mode of fire is done by the pull on the trigger - short pull produces single shots, and long, deliberate pull produces automatic (burst) fire. For semi-automatic fire only rifle is equipped with selector, which, when engaged, limits rearward travel of the trigger so only single shots can be squeezed out of the gun. This selector is located within trigge guard, above the trigger, and moves laterally. Because of bullpup layout, buttplate is attached directly to the receiver, and pistol grip and scope mount are moved forward. Barrel is shortened and equipped with combination flash hider / muzzle brake device. Integral folding bipod is attached to special rod, which runs forward from receiver. This is done to relieve the barrel from stresses generated by bipod. Early versions of SVU and SVU-A vere produced without bipod, and actually the "S" letter in SVU-AS designation stands for "soschka" (bipod in Russian). Standard sighting equipment includes open sights installed on folding bases, with rear being of diopter type and adjustable for range between 100 and 1300 meters. There's also a standard side rail, which will accept variety f telescope or night sights, the 4X PSO-1 being most typical. SVU-AS rifles use standard SVD magazines with 10-round capacity. Apparently, bigger capacity magazines were also designed for SVU-A, but it seems that none were produced in quantity.
The automatic fire feature of SVU-A and SVU-AS seems to be of any value only in emergency close combat or self-defense actions, as the limited magazine capacity and light barrel greatly limits automatic fire capabilities of this weapon.

Knights SR-25, Mk.11 Mod.0 and XM110 sniper rifle (USA)

Knights SR-25 rifle, civilian version with 20" barrel

Knights SR-25 carbine, civilian version with 16" barrel and telescopic buttstock

US Navy / USMC Mark 11 Model 0 (Mk.11 Mod.0) sniper rifle system, with 10-round magazine, daylight telescope sight and bipod

US Navy / USMC Mark 11 Model 0 (Mk.11 Mod.0) sniper rifle system, with 20-round magazine, daylight telescope sight and installed quick-detachable sound suppressor

US Army XM110 Semi-Automatic Sniper Rifle (XM110 SASR), with daylight telescope sight, bipod and quick-detachable sound suppressor

SR 25 rifleSR 25 carbineMK 11 Mod 0XM 110
Caliber7,62x51 NATO / .308 Winchester
SystemSemi-automatic, gas operated
Overall length1118 mm940 / 860 mm1158 mm1187 - 1200 mm
Barrel length508 mm (20")406 mm (16")508 mm (20")508 mm (20")
Weigth4,31 kg (less scope and magazine)3,86 kg (less scope and magazine)6,9 kg (with scope and bipod, less magazine)7,26 kg (with scope and bipod, less magazine)
Magazine10 or 20 rounds, detachable

The SR 25 rifle (Stoner Rifle, model 25) was developed by Reed Knight (owner of Knights Armament Co) and Eugene Stoner (designer of M16 and Stoner 63 rifles among other things) during early 1990s. In essence, the SR 25 was the AR-15 rifle scaled up to shoot 7,62x51 / .308 Win ammunition, with up to 60% of parts of new rifle being interchangeable with standard AR-15 components. This rifle sold well among civilian shooters who needed an accurate semi-automatic rifle in 7,62 / .308 caliber for hunting or target shooting. This rifle also found a favor among US Military - during early 1990s it was adopted by US Navy SEAL groups, as Mark 11 Model 0 sniper rifle system; use of Mk.11 Mod.0 rifle was later extended to US Marine Corps. Mark 11 Model 0 rifle system included the semi-automatic SR-25 rifle, a quick-detachable sound suppressor, also developed by Knights Armament Co, Leupold Vari-X Mil-dot telescope sight, Harris bipod, 20-round magazines and other necessary accessories. In 2005, a modified version of the SR-25 / Mk.11 rifle won US Army Semi-Automatic Sniper Rifle (XM110 SASR) competition, and today it is being issued to US Army snipers, in attempt to replace venerable M24 Sniper Weapon System. A certain controversy exists about this replacement, as some experts doubt that Knight's semi-automatic XM110 rifle could equal long-range accuracy of the bolt-action M24. However, Knights Armament Co claims that SR-25 is capable of 0.5 MOA accuracy with match ammo, and in the field Mk.11 or XM110 rifle can proved accurate and rapid fire out to 600 meters or even more, depending on particular circumstances and proficiency of operator. Use of quick-detachable silencer / sound moderator also has several benefits, the most obvious being concealment of the operator's position, as silencer decreases the sound of gunshot and completely eliminates muzzle flash. Another, less obvious benefit is that silencer also acts as an effective muzzle brake, decreasing recoil and thus permitting faster follow-up shots.

All rifles built on SR-25 platform share same basic action, which is based on AR-15 / M16 system. This is a gas-operated system with direct-impingement gas drive, which has no gas piston. Instead, powder gases are fed from the barrel and through a stainless-steel tube back into the receiver, and then into the cavity inside bolt carrier through the gas key. Inside the bolt carrier, powder gases push it back against the bolt, thus first causing the bolt to rotate and unlock from the barrel, and then to cycle the action. The rotary bolt has 7 radial lugs and improved extractor. Both upper and lower receiver halves are made from aircraft grade aluminum alloy, and connected by cross-pins. There is no "forward assist" button on the SR-25 rifles; the brass defelector is present. Barrels are of match class quality, and enclosed into free-floated forearm, fitted with Knights-made and designed Picatiny rails system. Because of AR-15-style recoil buffer, which extends rearwards fro the receiver, SR-15 cannot be fitted with folding buttstock; most rifles are fitted with fixed butt, while SR-25 carbines are fitted with telescoping buttstock. Trigger is also of match grade, fully adjustable.

Military versions of the SR-25, known as Mk.11 Mod.0 (USN / USMC) and XM110 (US Army) have some differences from civilian rifles. First of all, these rifles are fitted with proprietary sound moderator / silencer quick mount, located on the barrel just in front of the gas block. These rifles also finished to military specifications, and equipped with back-up iron sights (marked up to 600 meters and installed on folding bases). XM110 rifle also features a different buttstock, which is adjustable for length of pull, as well as different style forend rail system and a flash hider on the barrel. Military rifles are usually issued along with Harris bipod, Leupold variable-power 3,5-10X sniper scope, and a number of other accessories, including soft and hard carrying cases.

GL-06 40mm grenade launcher (Switzerland)

GL-06 grenade launcher with optional accessories such as Red Dot sight, forward grip and a tactical light

GL-06 grenade launcher with barrel opened up for loading

LL-06 - a dedicated less-lethal version of the GL-06, intended for police application, with array of available less-lethal and practice munitions

Caliber: 40x46mm low velocity
Type: single-shot
Overall length: 590 / 385 mm (stock opened / folded)
Weight: 2,05 kg unloaded
Effective range: up to 300 m

GL-06 grenade launcher is a dedicated stand-alone shoulder-firing weapon, intended for military and police applications. Designed by well-respected Swiss arms-making company Brügger & Thomet AG, GL-06 is already in use with certain European military Special Forces groups. A special dedicated "less lethal" version of GL-06 is produced as LL-06. It must be noted that the only difference between GL-06 and LL-06 is the color of the frame - both weapons are fully capable of firing a complete range of 40mm x 46 munitions.
It must be noted that GL-06 was born from recent request from police force of one of leading European nations, which sought to obtain a less-lethal weapon for anti-riot application, with particular need for pin-point accuracy at standoff ranges (beyond 40 meters for such scenarios) when firing impact rounds. B+T provided its client with both weapon and a special round, with added benefit of compatibility with wide array of lethal and less-lethal ammunition produced in 40mm low-velocity class. GL-06 is lighter and more compact than other stand-alone weapons of the same class (such as US M79 or German HK 69), yet it is capable of great accuracy, tactical flexibility and has good ergonomics.

GL-06 grenade launcher is a single shot weapon, with rifled tip-up barrel. For loading and unloading, rear part of the barrel is tipped up; therefore, rounds of any conceivable length can be easily loaded and extracted without problems. Barrel opening is assisted by special spring, thus speeding-up the reloading process. The barrel lock levers are fully ambidextrous and located in front of trigger guard, within the reach of the index finger. Trigger is of Double Action Only type, with concealed hammer. Additional manual safety is provided in form of the cross-bolt button located on the receiver above the pistol grip. GL-06 is provided with integral open sights (with adjustable diopter-type rear sight), and an integral Picatinny type rail on the barrel, which permits installation of many types of sighting equipment. Three additional accessory rails are installed on the short forend, below the barrel. GL-06 is fitted with side-folding butt, made of durable polymer, and is equipped with sling attachment points.

Saturday, November 24, 2007

SIG MG 710 machine gun (Switzerland)

SIG MG 710-1 (MG 57-1) machine gun

SIG MG 710-2 (MG 57-2) machine gun in light role, on bipod and with 50-round belt container attached

SIG MG 710-2 (MG 57-2) machine gun in medium role, on tripod and with 200-round belt in separate box

SIG MG 710-3 in light role, early model with wooden buttstock

SIG MG 710-3 in light role, with belt box attached, late production model with metallic buttstock

Data for SIG MG 710-3 machine gun

Caliber 7,62x51 NATO
Weight 9,25 kg (with bipod) + 10 (tripod)
Length 1146 mm
Barrel length 560 mm
Feed belt
Rate of fire 900 rounds per minute

In around 1955, following the successful testing of the prototype SIG assault rifle which used a retarded-blowback action, SIG engineers began development of a universal machine gun using the same principles. The basic design was derived from German MG 42V / MG 45 machine gun, but rollers were replaced by swinging flaps with rounded locking surfaces. The first SIG prototype, known as the MG 55, looked much like German MG 45, although the Swiss weapon was made to much higher standards. The MG 55 retained the MG 42 / MG 45-style barrel changing procedure, and in the following years SIG designers tried a variety of other barrel change systems, which, along with other minor changes, led to a series of prototypes, known as the MG 57-1, MG 57-2, and, eventually, SIG MG 710, which appeared in 1960. This gun was ready for production, and a few were made in 6.5x55 Swedish caliber for export; gun was also advertised in a number of other contemporary chamberings such as 7,92x57. Later on, SIG produced a similar weapon in 7.92x57, which was designated SIG MG 710-2, but this also was only made in very limited numbers. This one had different barrel change procedure and thus featured a shrt, tubular barrel jacket. In 1965 SIG presented the latest and most successful weapon of the MG 710 line – the SIG MG 710-3, chambered in 7.62x51 NATO ammunition only. It was somewhat different from previous weapons of the same series, as it featured a different barrel change system. This machine gun was sold in significant numbers to several South American and African countries. It must be noted that Swiss army never used SIG 710 machine guns, being entirely happy with 7,5x55 MG 51 machine guns.

The SIG MG 710 (also often referred to as the SIG model 710 or simply SIG 710) is an air-cooled, belt fed, retarded-blowback operated machine gun. The barrel is stationary but can be easily replaced through the opening in the right side of the relatively short barrel jacket. The barrel is fitted with a special handle on the right side which is used to remove hot barrels from the gun.
The locking system is based on the SIG Stgw.57 assault rifle, which, in turn, is an evolution of WW2-era German designs, either the Mauser Stg 45(M) or Grossfuss MG 45. The bolt group consists of two parts, a lighter head and a heavier body, with a pair of delaying levers inserted at either side at the front of the group. When in battery, the levers are engaged with cuts made in the barrel extension. Upon firing, gas pressure, via the base of the cartridge, pushes the bolt head back, and levers provide a mechanical disadvantage by accelerating the heavier bolt body. The system is so timed that the levers leave their recesses in barrel extension as soon as the bullet leaves the bore and pressure in barrel drops to safe levels. From this moment on, the bolt group is free to recoil under its accumulated inertia to complete the reloading cycle. To provide more reliable extraction, the chamber has several longitudinal flutes to allow some gas to "float" the case from the chamber walls.
The feed system uses non-disintegrating steel belts with open pockets. Feed is of the single-stage, push-through type, the belt being pulled from the left side only. The SIG MG 710 fires from an open bolt and the trigger unit permits automatic fire only.
In the light machine gun role the SIG MG 710 is used from an integral, folding bipod that is attached to the barrel jacket. In the medium role it can be used from a universal tripod, made by SIG. Early SIG MG 710-3 guns were fitted with wooden buttstocks; late production guns were made with tubular metallic butts.

MG 51 machine gun (Switzerland)

MG 51 machine gun in light role, on bipod

MG 51 machine gun in medium role, on tripod

Swiss soldiers firing the MG 51 machine gun (note that tripod is in low-profile position)

Caliber 7,5x55 GP11
Weight 16 kg (with bipod) + 26 kg (tripod)
Length 1270 mm
Barrel length 563 mm
Feed belt
Rate of fire 1000 rounds per minute

In around 1942 the Swiss army initiated a competition for a new service machine gun to replace both the “heavy” MG 11 and the “light” Lmg 25, adopted in 1911 and 1925 respectively. Three participants joined the competition – government-owned Waffenfabrik Bern, and privately owned factories SIG and Hispano-Suiza.
Waffenfabrik Bern based its development on the very successful German MG 42. The first prototypes emerged in around 1944, and looked much like MG 42, although the shape of receiver and butt was somewhat different. The final design, which appeared in 1950, was in most respects similar to the MG 42, although many parts were produced by machining instead of stamping, and the locking system was changed from roller to flap locking. The resulting weapon was heavier than the German original, and much more finely made and finished. In certain respects it was a “Rolex” of machine guns.
Until very recently MG 51 served as a primary infantry and vehicle machine gun for Swiss army, although it is now being gradually replaced in service with lighter and less expensive, but also less powerful 5,56mm FN Minimi machine gun of Belgian origin and manufacture.

The MG 51 is a short-recoil operated, locked breech, air-cooled and automatic only, belt-fed weapon. It uses a modified MG 42 type locking system with a two-piece bolt and dual locking flaps located in the front part of the bolt. These flaps engage the cuts made in the short barrel extension to provide rigid locking. Upon recoil, the flaps are retracted toward the center of the bolt, to unlock it. An additional lever-type bolt accelerator is provided; it is located in receiver, next to the barrel breech and below the bolt. The gun housing also somewhat resembles the German MG 42, although it is made from two separate parts – the barrel jacket (made from stamped steel) and receiver (a solid machined body). The barrel jacket is permanently welded to the front of the receiver. The barrel can be changed rapidly if required; the barrel change procedure is similar to that of the MG 42, with the locking latch located at the right side of the jacket, which is opened to provide a barrel replacement window.
The belt feed system is also similar to the MG 42, with single-stage cartridge feed that uses open-pocket steel belts (push-through type) and a two-stage belt pull (on both the opening and closing movement of the bolt). Feed is from the left side. For the mobile role, 50-round belts can be loaded into drum-type containers, which are clipped to the side of the gun.
Standard sights are of the open type, but telescopic or night sight can be fitted to the gun if necessary. A folding bipod is fitted; for sustained or long range fire missions a universal tripod is provided. Early production guns had wooden pistol grips and buttstocks; more modern guns have polymer furniture.

SIG MG50 / M/51 machine gun (Switzerland)

SIG MG50 (M/51) machine gun in .30-06 caliber in 'light' role, on bipod

SIG MG50 (M/51) machine gun in 'medium' role, on tripod and with telescope sight

Caliber 6.5x55, 7.5x55, 7.62x63 (.30-06) and 7.92x57
Weight 13.4 kg (with bipod) + 19.7 kg (SIG tripod)
Length 1245 mm
Barrel length 600 mm
Feed belt
Rate of fire Selectable, 600-700 and 900-1100 rounds per minute

When in early 1940s the Swiss army requested a new, universal machine gun to replace old Maxim and Furrer guns of pre-war design, SIG company decided to develop an indigenous design, and between 1944 and 1951 turned out a series of gas-operated machine guns, fed using either twin-drum magazines or belts. SIG MG 50 machine gun lost the Swiss trials to rival weapon designed by Waffenfabrik Bern (MG51), but continued for a while as a commercial venture. A definitive version of this design was adopted by Denmark in .30-06 caliber as SIG M/51; a version of the same gun, chambered in 6.5x55 was tested in Sweden as SIG MG53 but without success.

The SIG MG 50 is a gas operated, air-cooled, belt fed machine gun which fires from an open bolt in automatic mode only. The barrel is quick-detachable; its rear part, along with gas system below it, is enclosed by a tubular jacket without any cooling slots. The gas system is of the short-stroke type, and the gas cylinder is integral to the beech part of the barrel, so upon barrel replacement the gas cylinder and gas piston are also removed along with the barrel. The barrel is locked by a tilting bolt. Feed is via non-disintegrating belts assembled from 50-round lengths; the standard capacity is 250 rounds for tripod- or vehicle-mounted applications or 50 rounds (in a drum-type box) for light (bipod mounted) applications. Feed direction is from the left side only; empty cases are ejected downward through the aperture in the bottom of receiver.
The SIG MG 50 is fitted with a folding, non-detachable bipod which is attached to the front of the barrel jacket. For sustained fire missions the gun could be mounted on a special lightweight tripod.

AAT M.52 / Mod. F1 machine gun (France)

AAT M.1952 machine gun in light role, on bipod, left side

AAT M.1952 machine gun in light role, on bipod, right side

AAT M.1952 machine gun in medium role, on tripod

Caliber 7,5mm French (AAT-52); 7,62mm NATO (AAT F-1)
Weigth ca. 10 kg on bipod with light barrel; ca. 23 kg on tripod with heavy barrel
Length 1245 mm with long (heavy) barrel
Length of barrel 500 or 600 mm
Feeding belt 50 or 200 rounds
Rate of fire 700 rounds per minute

French armed forces got their own universal machine gun in 1952 with adoption of the AAT Mle.52 (Arme Automatique Transformable Modele 1952, or transformable automatic weapon model 1952) machine gun in 7.5mm caliber, developed by MAC (Manufacture d’Armes de Chatellerault). It was tested against several other designs, including a MAS M1950 prototype, a gas-operated universal machine gun with combination box magazine / belt feed. AAT M52 is a slim-looking weapon of indigenous design, available in a number of versions (light infantry on bipod and with light barrel, medium infantry on tripod and with heavy barrel, vehicle with heavy barrel). It was not without certain flaws, however, the most important being its retarded blowback action, which is sensitive to headspace adjustments and the timing of the bolt / retarder group. This gun, along with the older M1924/29 light machine gun, served with the French army through the Indo-China and Algeria campaigns, and is still the primary universal machine gun of French armed forces. With the transition to the NATO standards, the M52 machine gun was adapted to the 7.62x51 NATO ammunition, and got re-designated as AAT F1. The AAT M52 / F1 guns are now old, and at the time of writing France had expressed interest in acquiring a replacement GPMG. It seems probable that this will be a foreign design.

The AAT Mle.52 is a retarded blowback operated, air cooled, belt fed, automatic machine gun which fires from an open bolt. Barrels are quick-detachable and available in two versions – “light” (intended for the LMG role) and “heavy” (intended for sustained fire role).
The AAT Mle.52 uses a modified delayed blowback action originally designed by Pal Kiraly before WW2. In this system, the initial opening of the bolt is retarded by a lever which is installed between the light bolt head and the relatively heavy bolt body. When the bolt is in battery, a short arm of the lever rests against a recess in the receiver wall, and the long arm rests against the bolt body. Upon recoil, this lever, which is attached via a pivot to the bolt head, rotates to accelerate the heavy bolt body relative to the bolt head, thus slowing down the initial movement of the bolt head. Once the pressure in the barrel is low enough, the retarding lever exits the recess in receiver, and the bolt group continues its recoil cycle as one unit, extracting and ejecting the spent case on the opening movement and then loading and firing a fresh cartridge if the trigger remains pressed. To assist reliable extraction, the gun has a fluted chamber. While this locking system is relatively simple, it is quite sensitive to headspacing and also permits a lot of fouling, created by burning powder, to get inside the receiver.
The belt feed is more or less a copy of the German MG 42 feed, and is operated by a stud on the top of the bolt body. Feed is from the left side, using disintegrating belts with open pockets. In the 7.62 NATO version, this gun uses American M13 links.
Standard furniture includes a telescoping butt, made of stamped steel, a stamped steel pistol grip with plastic grip panels, a carrying handle and a folding bipod, both attached to the barrel. In the light role the AAT Mle.52 can be fitted with an optional rear monopod; in the sustained fire role, it is installed on a modified US M2 tripod using a special adaptor with traverse and elevation mechanisms. It must be pointed out that while the barrel change procedure for the AAT Mle.52 is quick in theory, in practice it could be less comfortable when the gun is used from a bipod. Since the bipod is attached to the barrel, the gunner has to hold the gun in his hands while his Number 2 replaces the barrel. When the gun is used from more substantial mount, i.e. tripod or vehicle, this is no problem as the mounting via the receiver supports the gun

W85 heavy machine gun (PR China)

W85 heavy machine gun on universal mount

Chinese soldiers aim with the W85 heavy machine gun

Caliber: 12,7x108
Weight: 18,5 (gun) + 17,5 (tripod)
Length: mm
Length of barrel: mm
Feeding: belt
Rate of fire: 550-600 rounds/min

The W-85 heavy machine gun at the first glance looks much like the Type 77 heavy machine gun, but closer examination reveals certain differences, such as very thick gas tube below the barrel (which conceals a conventional gas piston, as opposed to piston-less system of the Type 77 and Type 85), and the receiver is of generally rectangular cross-section, while the receivers of the Type 77 and Type 85 are more or less of tubular design. It is believed that the W-85 was built in parallel with the Type 85 HMG, most probably on a competitive basis, but lost in the PLA trials. Apparently, it survived as a commercial venture, as available information suggests that the NORINCO Corporation sold for export at least some armored vehicles armed with a “W-85 12.5mm machine gun”. Recently, information has surfaced in Chinese publications about the “new” 12.7mm QJC 88 tank machine gun, which looks exactly like the tank version of W-85.

The W-85 heavy machine gun is a gas operated, air cooled, belt-fed, automatic only weapon. Its design is loosely based on the Soviet DShKM / Chinese Type 54 heavy machine gun, although there are many differences in various subsystems.
The W-85 uses a long-stroke gas piston, located below the barrel. The piston is rigidly attached to the bolt carrier, which carries a compact breech block (bolt). The locking system can be described as an “inverted” Degtyarov / Kjellman flap lock; it uses two pivoting flaps, one at either side of the bolt, to engage cuts in the receiver walls. The key difference between the W-85 and DShKM is that, in the W-85, the flaps are pivoted at the rear and have special locking projections that lock into the receiver walls.
The feed is also broadly based on that of the DShKM, and the feed module is a detachable unit, attached to the top of the receiver. It is operated by a swinging arm which projects down at the right side of the feed. The fork-shaped bottom end of the arm engages a reciprocating charging handle, which is attached to the bolt carrier. Feed is from the left side.
The gun fires from an open bolt, in automatic mode only. The firing pin is operated by a projection on the bolt carrier; the same projection forces the locking lugs outwards so the gun cannot fire unless the bolt is fully locked. A manual trigger is fitted to the rear of the receiver, and dual spade grips provide firing controls. W-85 can be installed either on universal tripod, or on vehicle (tank) mounts.