CHALLENGER 2

The Challenger 2 is the first British Army tank since World War II to be designed, developed and produced exclusively by a single prime contractor, Vickers Defence Systems, with set reliability goals laid down in the fixed price contract. Challenger 2 was designed and manufactured at both Vickers sites, Barnbow Leeds and Scottswood Newcastle.

The hull and automotive parts of the Challenger 2 are based upon its predecessor Challenger 1, but Challenger 2 incorporates over 150 improvements aimed at increasing reliability and maintainability. The turret of Challenger 2 is a totally new design. Armour is an uprated version of Challenger 1′s Chobham armour. The Challenger 2 is the best protected tank in NATO (10) incorporating Chobham second-generation armour plating. Its NBC (nuclear, biological and chemical protection) system is capable of dealing with all known threats and, for the first time in any British tank, the crew compartment has both a heating and a cooling system.

The main armament consists of a Royal Ordnance 120 mm rifled tank gun designated the L30. It also incorporates a McDonnell Douglas Helicopter Systems 7.62 mm chain gun, which is already in service in the British Army, being installed in the GKN Defence Warrior mechanized combat vehicle, and a 7.62 mm anti-aircraft machine gun. The Challenger 2′s fire control system is the latest-generation digital computer from Computing Devices Company (CDC) of Canada and is an improved version of that installed in the US M1A1 Abrams tank. It also has growth capacity for future enhancement such as a Battlefield Information Control System and navigation aids. The Challenger 2 carries a crew of 4 and has a combat weight of 62.5 tonnes. It has a maximum road speed of 56 km/h and a range of 250 km cross country and 450 km on the road.

The Challenger 2 (CR2) project includes the development and production of 386 CR2 Main Battle Tanks (MBTs), 22 Driver Training Tanks (DTTs), CHARM 3 ammunition and a full support package including training equipment and initial spares.

Prime Contractor was Vickers Defence Systems plc. Vickers Defence Systems started work on the Challenger 2 in November 1986 as a private venture and shortly afterwards, in March 1987, made its first presentation of the vehicle to the British Ministry of Defence. In February 1988, Vickers submitted a formal proposal regarding the tank to the MOD following the issue of the staff requirement. In December 1988 it was announced that Vickers Defence Systems was to be awarded a £90 million contract to undertake a demonstration phase (also referred to as the proof of principle phase) which lasted until September 1990. Vickers Defence Systems acquisition was completed on 30 September 2002, by Alvis PLC.

The operations of Vickers Defence Systems were merged with those of Alvis’ existing UK armoured vehicle company,Alvis Vehicles Ltd, in a combined UK business. In order to benefit from the heritage and reputation of both Alvis and Vickers, it has been decided to call the combined UK company Alvis Vickers Limited (Telford, UK). This company was then acquired by BAE Systems, to form BAE Systems’ new Land Systems business through the bringing together of Alvis and RO Defence.

In June 1991 the British Government selected the Challenger 2 and placed an order worth £520 million for 127 Challenger 2 MBTs and 13 driver training tanks. Production began in 1993 and the first vehicles were delivered in July 1994. The Challenger 2 is produced at the Vickers Defence Systems plants in Leeds and Newcastle. There are over 250 subcontractors (both UK and Overseas) involved at some point in the manufacturing process. Among the most significant are: Royal Ordnance (Main and Secondary armaments); Blair Catton (Track); and GEC-Marconi (Gun Control).

The requirement to replace Challenger 1 (CR1) MBT led to the placement of a follow-on order with Vickers Defence Systems. In July 1994, Vickers Defence Systems received a further order from the UK MOD for the supply of 259 Challenger 2 and nine driver training tanks plus training and logistic support. The total value of the contract was £800 million.

The CR2 In-Service Reliability Demonstration (ISRD) milestone was successfully achieved in January 1999. The ISRD took place from September to December 1998 and tested 12 British Army crewed MBTs at the Bovington test tracks and Lulworth Bindon Ranges. The ISRD was a great success in that CR2 not only achieved the targets but exceeded them in all areas set by the Customer’s Staff Requirement.

The Royal Scots Dragoon Guards in Germany, the first of six post-SDR Armoured Regiments, started to take delivery of CR2 in January 1998 and received the 38th in time to meet the June 1998 in-service date. Deliveries of CR2 are continuing and it is planned that each of the six Armoured Regiments will be fully equipped with their tanks and associated logistic support package by end of 2000.

The conversion from CR1 to CR2 Regiments is being assisted by a comprehensive suite of training aids, ranging from simple wall charts to highly sophisticated, computer-based gunnery simulators. A range of CR2 training aids and support equipment are also being provided for the Royal Electrical and Mechanical Engineers (REME) to assist the task of fault diagnosis, test, repair, calibration and system performance monitoring.

The Challenger 2 (CR2) project includes the development and production of 386 CR2 Main Battle Tanks (MBTs), 22 Driver Training Tanks (DTTs), CHARM 3 ammunition and a full support package including training equipment and initial spares. Following international competition for a requirement to replace Chieftain MBT, a contract was placed with Vickers Defence Systems in June 1991 and included production of 127 CR2 MBTs and 13 CR2 DTTs. The requirement to replace Challenger 1 (CR1) MBT led to the placement of a follow-on order with Vickers Defence Systems during July 1994 for an additional 259 CR2 MBTs and nine CR2 DTTs.

The CR2 In-Service Reliability Demonstration (ISRD) milestone was successfully achieved in January 1999. The ISRD took place from September to December 1998 and tested 12 British Army crewed MBTs at the Bovington test tracks and Lulworth Bindon Ranges. The ISRD was a great success in that CR2 not only achieved the targets but exceeded them in all areas set by the Customer’s Staff Requirement.

The Royal Scots Dragoon Guards in Germany, the first of six post-SDR Armoured Regiments, started to take delivery of CR2 in January 1998 and received the 38th in time to meet the June 1998 in-service date. Deliveries of CR2 are continuing and each of the six Armoured Regiments was fully equipped with their tanks and associated logistic support package by end of 2001. The last of the British Army’s 386 Challenger 2 Main Battle Tanks has been delivered by contractors at a ceremony on Salsibury Plain, by September 17, 2002.

The conversion from CR1 to CR2 Regiments was assisted by a comprehensive suite of training aids, ranging from simple wall charts to highly sophisticated, computer-based gunnery simulators. A range of CR2 training aids and support equipment was also provided for the Royal Electrical and Mechanical Engineers (REME) to assist the task of fault diagnosis, test, repair, calibration and system performance monitoring.

Deployed with six Regiments of the Royal Armoured Corps in the UK and Germany, the Challenger 2 Main Battle Tank has seen service in Bosnia and Kosovo and exercised in Canada, Oman and Poland. It has surpassed reliability targets on both trials and on exercises. British Army Challenger 2 tanks were deployed on active service in Operation Iraqi Freedom.

In July 2004, the UK Ministry of Defence announced plans for a reduction of seven Challenger 2 armoured squadrons (about 100 tanks) by March 2007 and the change of role of one Challenger 2 regiment to an armoured reconnaissance regiment.

Challenger 2E, the latest development model, has been designed for the export market and is suitable for harsh environmental and climactic conditions. The 2E has been extensively trialled in Greece, Qatar and Saudi Arabia.

New Main Gun for the Challenger 2: The Rheinmetall 120mm L55.

In January 2004, BAE Systems Land Systems (formerly RO Defence) was awarded a contract to develop a new smoothbore 120 mm gun for the British Army Challenger tanks. Under the contract, a Challenger 2 has been armed with the new Rheinmetall L55 smoothbore gun, as fitted on the Leopard 2A6 main battle tank, and began firing trials in January 2006.

Ballistically the new weapon is the same as the German 120 mm L/55 but externally can fit into the space previously occupied by the L30. The current Challenger 2 installation retains the L30 rifled gun’s cradle, gun clamp, thermal sleeve, fume extractor and muzzle reference system. Following trials in Germany the weapon was also tested in a static mount installed on a Centurion MBT chassis in mid-2005 and later in the same year, was finally integrated into a Challenger 2 MBT.

This upgrade will enable the British main battle tank to use NATO-compliant 120mm ammunition.

Static firing trials have already been conducted against a wide range of targets firing the Rheinmetall 120 mm DM53 APFSDS projectile with a conventional penetrator. These trials, although classified information, seem to have shown that the DM53 round gives enhanced performance over the previous 120 mm Challenger Armament – CHARM 3 – firing a depleted uranium round.

Challenger 2E

Challenger 2E has been specifically designed for demanding environmental and climatic conditions and represents the latest evolution of the highly effective family of Challenger vehicles.

The Challenger at the Gulf War

The Vickers Challenger was bought for the British Army after the Shah of Iran was deposed and the order blocked. It was developed from the Chieftain but was much faster, better armed and armoured but suffered from a weak fire control system. The Challenger gave the British Army a state-of-the-art tank ten years before any replacement for the Chieftain was scheduled. The Challenger was made for the desert, but did not have the chance to win its spurs until the Gulf War.

Actually, Vickers did not manufacture all the Challenger 1 MBTs, only the last regiment. Challenger 1 was built at the Royal Ordnance Factory (ROF) Leeds (it became Royal Ordnance in preparation for privatization), which Vickers bought just before the order for the 7th regiment was placed.

Fitted with a 120mm L11 A5 gun, the Challenger’s only weakness was its fire-control system, which had been upgraded by the Gulf War. The gun could penetrate 400mm of armour and destroy any Russian-built tank with a single hit. With nearly all of Iraq’s’ tanks being Russian built, the Challenger was able to deal with them easily. Backed up by the massive air support and alongside the Arab, French and American tanks the Allied armour ripped through the Republican Guard without much trouble. The Challengers in Desert Storm mainly employed HESH (High Explosive Squash Head) shells with their longer range as the Iraqi tanks armour wasn’t up to Russian standards and would have been a waste of the shorter-ranged high-density armour-piercing rounds.

TURRET AND HULL

The tank accommodates four members of crew, the commander, gunner, driver and the loader, for increased fightability and effective round-the-clock operation, which is strongly influenced by the number of crew which can be carried. The commander’s station is on the right and is equipped with eight periscopes, magnification x 1, which provide 360 degree vision. Pushing a red command button under each periscope causes the turret to slew round to align with the periscope. The gunner is seated in front of and below the commander, and the loader is seated on the left. The loader’s station is equipped with a periscope. The driver’s compartment is at the front of the tank.

WEAPONS

Challenger 2 is equipped with an L30, 120 mm rifled tank gun from the Royal Ordnance division of British Aerospace Defence Ltd at Nottingham, UK. The L30 construction incorporates a chromium lining which provides a harder and smoother internal surface. The chromium lining gives increased velocity and therefore penetration power to the round, greater precision and reduced wear on the barrel. The gun is made from electro-slag refined steel (ESR) and is insulated with a thermal sleeve. The gun is fitted with a muzzle reference system and fume extraction to remove the gasses from the barrel. The turret is capable of 360 degree rotation and the weapon elevation range is from -10 to +20 degrees.

The target engagement sequence has been designed for simplicity of operation in battlefield conditions. The same engagement sequence is followed for static and moving targets in daylight or by night. The gunner or the commander aligns an aiming mark on the target, presses the laser rangefinder button and then presses the fire button.

The 120 mm L30 gun fires all current 120 mm ammunition. There is capacity for 50 projectiles, which can be a mix of armour piercing fin stabilized discarding sabot (APFSDS), high explosive squash head (HESH) or smoke rounds. The L30 gun can also fire the Depleted Uranium (DU) round with a stick charge propellant. Depleted Uranium has a density approximately two and a half times higher than that of steel and the mass of the DU projectile provides high penetration characteristics. The first depleted uranium round, the L30, is part of the Charm 1 gun, charge and projectile system. A Charm 3 system is under development in which the depleted uranium projectile has a higher length to diameter aspect ratio for increased penetration performance. The ammunition, being of the separate projectile and charge loading type, allows the explosive ammunition to be stowed below the turret ring. Armoured bins provide the stowage for the charges.

The gun control is provided by an all-electric gun control and stabilization system from GEC Marconi Radar and Defence Systems of Leicester, UK. The Challenger 2 is also equipped with a McDonnell Douglas 7.62 mm chain gun, which is located to the left of the main tank gun. The loader seated on the left hand side has a 7.62 mm GPMG anti-air machine gun, type L37A2, mounted on the cupola.

On each side of the front of the turret are five L8 smoke grenade dischargers, from the Helio Mirror Company of Kent, UK. The Challenger 2 can also set a smoke screen by the injection of diesel fuel into the engine exhausts.

The Challenger 2 is equipped with a Military Standard 1553 data bus. The fire control computer is a digital computer from Computing Devices Company of Ontario, Canada. The digital CDC computer has capacity for additional systems, for example a Battlefield Information Control System, and navigation and training systems.

In January 2004, BAE Systems’ Land Systems was awarded a contract to develop a new smoothbore 120mm gun for the British Army Challenger tanks. Rheinmetall of Germany will provide examples of the L55 smoothbore gun fitted on the Leopard 2A6 for the program. A technical demonstrator will be produced by 2006.

SENSORS

The commander has a Gyrostabilized site, model VS 580-10, from SFIM Industries of France. The upper unit of the VS 580, containing the Gyrostabilized panoramic sight and electronics, is mounted on the turret roof. A neodinium yttrium aluminium garnet, Nd:YAG, laser rangefinder is incorporated into an intermediate assembly which joins the upper unit to a lower telescope assembly inside the turret. The telescope assembly houses the optical viewing system, hand controls, electronics and the sight stabilization system. The sight provides all round vision without the commander having to move his head. The elevation range is plus or minus 35 degrees. The field of view with x 3.2 magnification optics is 16.5 degrees, and with x 10.5 magnification optics, the field of view is 5 degrees.

A thermal imager, the Thermal Observation and Gunnery Sight II, TOGS II, from Pilkington Optronics of Glasgow, UK, provides night vision. The sensor is the UK TICM 2 thermal imager. The imager is mounted inside an armoured barbette above the gun. An on-board compressor and gas bottle pack provide cooling for the imager. Symbols are overlaid on the thermal image to show the aiming marks and system status data. The thermal image, with magnification x 4 and x 11.5 is displayed in the gunner’s and commander’s sights. The thermal image is also displayed on relaxed-viewing monitors in the commander’s and gunner’s stations.

The gunner has a stabilized Gunner’s Primary Sight, GPS, from Pilkington Optronics of Glasgow, UK. The sight consists of a sight body with a visual sighting channel, a head unit with a stabilized aiming mirror, a 4 Hz neodinium yttrium aluminium garnet Nd:YAG laser rangefinder and a display monitor with a monocular eyepiece. The laser rangefinder with wavelength 1.064 microns, operates over the range 200 meters to 10 kilometers. The range accuracy is plus or minus 5 meters and the discrimination is 30 meters The gunner is also equipped with a reversionary mode telescope, model L30, from Nanoquest, mounted coaxially with the main gun.

The driver is equipped with a Passive Driving Periscope, PDP, from Pilkington Optronics. The periscope uses a night vision image intensifier device. At night the tank is able to achieve speeds comparable to day-time speeds using the passive driving periscope and without the use of artificial light.

The Military Standard 1553 data bus interfaces the Gunner’s Primary Sight and the thermal imaging system to the fire control computer.

ENGAGEMENT PROCEDURE

The commander aligns the roof mounted panoramic sight on a target and presses the align switch to slew the turret round until the gun is automatically positioned on the target. The gunner then takes over the engagement of the target, and presses the laser rangefinder and the fire buttons to fire the gun. As soon as the gunner has taken over the engagement of the target, the tank commander is able to locate and take range measurement of a second target using the commander’s sight. The data for both targets, the first target being engaged by the gunner and the second target, are stored in the digital fire control computer. When the gun has been fired and the kill assessment on the first target completed, the commander presses the align switch which results in the turret slewing round to align the gun on the second target and automatically firing the gun. The operational procedure greatly enhances the firepower of the tank, in that the Challenger can effectively engage targets in rapid succession.

SAFETY

The design of Challenger 2 has given emphasis to crew safety and tank survivability. The turret is protected with second generation Chobham armour which provides increased resistance to penetration by anti-tank weapons. The tank is protected against nuclear, biological and chemical (NBC) warfare by an NBC protection system (with full overpressure filtered air) located in the turret bustle. The electronics systems are protected against nuclear electromagnetic pulse (EMP).

The movement of the turret and gun is by a solid state electric drive rather than by high pressure hydraulic drive. The electric drive removes the risk associated with rupturing of high pressure hydraulic hoses in the crew compartment. The stowage for explosives is below the turret ring which provides a less vulnerable position than in the turret bustle.

The turret and the hull designs incorporate stealth technology to minimize the radar signature.

TRIALS

Challenger 2 has successfully completed trials with the British Army and the Royal Army of Oman. All the performance parameters were demonstrated, including the weapon systems, reliability and survivability. The performance of the Chobham armour was demonstrated in repeated firings trials on the Challenger 2 turret with modern anti-tank weapons. The result of the trial was that the complete turret survived without penetration and the sighting system allowed the gun to be laid and fired.

PROPULSION

The Challenger 2 has a 12 cylinder 1200 horsepower diesel engine, from Perkins Engines (Shewsbury) Ltd of Shropshire, UK., and a David Brown gearbox, model TN54, with 6 forward and 2 reverse gears. The maximum speed by road is 59 kilometer/hour and mean speed 40 kilometers./hour cross country. The range is given as 450 kilometers. by road and typically 250 kilometers. cross country.

Challenger 2 characteristics, technical performance, and specifications:

General characteristics / technical performance

Engine: Perkins Condor CV12 1200bhp
Gearbox: David Brown TN54 epicyclical, 6 fwd 2 rev
Suspension: Hydrogas variable spring rate
Track: William Cook Defence; hydraulically adjusted double pin
Speed: 59 kph (road); 40 kph (mean cross country)
Main Armament: Royal Ordnance 120mm L30 gun
Ammunition: CHARM 3, HESH and Smoke
Secondary Armament: Hughes 7.62mm coaxially mounted chain gun and 7.62mm loader’s hatch mounted GPMG
Smoke Dischargers: Exhaust smoke injection and two sets of five L8 grenade dischargers
Commander: Gyrostabilized fully panoramic site with laser range finder and thermal imager
Gunner: Gyrostabilized primary site with laser range finder and thermal imager, and coaxially mounted auxiliary sight
Driver: Day and night periscopes
Loader: Day periscope

SPECIFICATIONS

“Stealth” bombers B-2 firstly attempted great interest when appeared first information in public press about ability of creation “stealth” bomber in USA at the end of 70-ties. Firstly classified and modernized first bomber was officially presented at the press conference in Washington on 22 July 1980. The greatest part of information remained secret and the conference was organized to prevent spreading title-tattle information filling public press for a last few months.

In 1975 US Air Force was seriously interested in “stealth” aircraft. It made contract with Lockheed corporation to project and produce “stealth” fighters. There were created some models and one of them got indexation F-117. Later in 1985 US Air Force made order in Northrop for “stealth” bomber production. Northrop’s experience in low radar visibility technology was more than 50 years then.

Northrop’s constructors developed aircraft with “low radar visibility”. They developed “stealth” bomber with rounded shapes to ensure better radar signal spreading, suppressing their regressive reflection. Four reaction engines, fuel tanks and armament were placed inside the bomber. B-2 has special cover, called RAM, absorbing radio waves. This cover is made from composite materials based on plastic. Pilot cockpit glass is covered with transparent gold coat. This coat helps to suppress radar waves regressive reflection from pilots helm and other internal cockpit equipment..

In 17′th July 1989 after almost decade of developing first B-2 looking like a bat took of the ground. Two US Air Force fighters F-16 were leading B-2 in it’s first flight upon California dessert near Edwards military base. B-2 was piloted by two test-pilots at a quiet low speed and altitude, reaching only 3 000 m limit. After two hours bomber was returned to airbase. It’s developing cost 22 milliards of dollars and made it the most expensive aircraft in the history. Single bombers price is approximately 2.1 milliard of dollars.

Bomber is controlled by a half-automatic control system Computer permanently controls flight and automatically corrects yokes position. Pilot is controlling bomber also by giving orders to computer.

B-2 was projected with for special purposes. In case of war it could deeply intrude into enemy’s territory and drop nuclear bombs on ballistic intercontinental missile loading shafts. B-2 was also able to strike against ground command centers to eliminate enemies command staff. Additional B-2 tasks are to search and destroy mobile enemies mobile missile loading platforms. Bomber was firstly used in military conflict in Yugoslavia in 1999.

From 1991 when B-2 entered service in US Air Force there were built 20 “stealth” bombers.

Main battle tank T-90 was developed in the early 90-ties by Uralvagonzavod plant design bureau (leading designer V.Potkin). It was published as a main Russian army tank till the year 2005. Since 1997 it’s export modification T-90S has been offered in the world’s military markets. In “Military Ordnance” magazine opinion T-90S took 7-th place in the world best main battle tanks rating in 1998.

Main battle tank’s T-90 construction embodies the best main battle tank T-72B and T-80U design solutions and the best layout and structural features. From T-72B it got reliable and well recommended chassis, from T-80U – turret with armament and fire control systems. A number of constructional decisions were made using modern combat experience and reorientation to Russian complement.

Main battle tank has classic arrangement, with rear placed engine and transmission. Tanks crew consists from commander, gunner and driver-mechanic.

Driver is placed in hull’s front part under his hatch in separate driving compartment. He is fitted with wide view optical system. Tank’s commander and gunner are placed in rotating armored turret, in combat compartment. Commander is placed right from main gun and gunner – left.

T-90 armor is made from filled multi-layer combined armor, with built-in dynamic defense “Kontakt-5″, which consists from eight sections in upper hull’s frontal armor and three anti-cumulation screens from each side. Low silhouette turret has built-in seven blocks and one container. 20 more containers are placed on the turret roof. Last mentioned provide protection from helicopters, attack aircrafts and perspective anti-tank missiles, defeating tank threw it’s turret’s roof.

Additional defense is provided by TShU-2 “Shtora” optical-electronical countermeasure complex. This complex decreases anti-tank guided missile, with half automatic guiding system, hit probability in 70 – 75% and makes strays for laser guided systems and laser based rangefinders. Complex consists from optical-electronical suppression station TShU-1 and aerosol screen making device. Last mentioned consist from two modules (infrared flashlights) placed in turret’s frontal part and making coded infrared signals, preventing correct missiles guidance. Aerosol system registers irradiance by laser sight, designates irradiation source location, chooses on from 12 smoke grenade launcher placed from both turret sides, makes electric signal proportional to angle needed to turn turret with grenade launchers, and fires aerosol grenade on 55 m distance. This measure provides protection from laser guided anti-tank missiles.

As much as aerosol screen devices are used from 902B “Tuchia” smoke grenade launchers, it makes available to use smoke grenades ZD6 covering tank from visual and infrared notifying.

Smoke screens can be also set with thermo smoke device, generating smoke from fuel.

Main armament is 2A46M, 125-mm mm smoothbore gun. It is fitted with two plane stabilizer 2Je42-4 and automatic reloading mechanism. To increase fire accuracy and prevent overheating barrel is fitted with dismantling 4-section thermal sleeve. Ammunition load is similar to T-80U and contains armor-piercing, cumulative and high explosive-fragmentation projectiles. Furthermore there was developed high explosion-fragmentation projectile with electric remote detonator. Ammunition load also contains 9K119M “Refleks” complex (Nato codename AT-11 “Sniper”) anti-tank guided missiles. Missile flying range is 4 000 m what allows T-90 to defeat the biggest part of enemy tanks and helicopters without entering their reach ability limit.

Tank has modernized fire control complex 1A45 which contains fire control system 1A42, guided missile complex 9K119, commanders observation complex PNK-4S, guiders laser sight-rangefinder 1G46 and tank’s thermo vision complex TO1-PO2T. Necessary target pointing data is provided by ballistic computer 1B528-1 with input information sensors. Overall fire control system allows to defeat targets at day-night conditions by artillery fire in movement and guided missiles – from short stops.

Main battle tank’s addition armament consists from 7.62-mm coaxial machine gun PKT and 12.7-mm anti-aircraft machine gun NSVT, placed in anti-aircraft closed type device with fire control system 1C29, stabilized in vertical plane. This system allows commander to fire with closed hatch.

T-90 engine is well built and recommended V-84MS two stroke, six cylinder, multi-fuel diesel with 840 h.p. power.

Tank’s chassis is constructional similar to T-72B chassis. Suspension consists from six large rubber-laid bearing rolls, directing and tracking spider and supporting rolls from each side. First, second and sixth bearing rolls are fitted with absorbers. From the sides tracks and suspension are covered with anti-cumulative screens.

Speed and maneuverability characteristics are the same as T-72B. Main battle tank’s T-90 export modification T-90S is fitted with increased power multi-fuel 1 000 h.p. diesel engine with gas turbine injection. Tank is fitted with air conditioning system for work in high temperature zones.

T-90 hull’s frontal part is fitted with retraceable device and mine trawl KMT-6 connection hardpoints.

On main battle tank’s T-90 base there was also developed T-90SK – command version intended for export. It has additional three channel communication (reaches 50 – 250 km range marching) and unremitting tank’s coordinates receiving and indication equipment.

The first Soviet ‘true’ intermediate cartridge (7.62×41 M43) assault rifle, Sudaev AS-44, as tested in 1944. Unfortunately, Sudaev fell severely ill in 1945 and died next year before finalizing his design.

Tokarev 7.62×41 experimental assault rifle, as tested in late 1945


The first Kalashnikov assault rifle prototype of 1946, also known as AK-46. Note that it had numerous internal and external differences from the later models, including separate safety and fire mode selector switches, as well as non-reciprocating charging handle, all located on the left side of the weapon

AK-46 prototype disassembled

The Bulkin AB-46 experimental assault rifle, which greatly influenced the AK-47

The experimental Kalashnikov assault rifle of 1947, also known as AK-47, first model

Bulkin AB-46 experimental assault rifle, partially disassembled.

The experimental Kalashnikov assault rifle of 1947, also known as AK-47, first model, disassembled

The experimental Kalashnikov assault rifle of 1947, also known as AK-47, second model (note that it has a small muzzle brake / compensator)

Early production / issue Kalashnikov AK rifle, as manufactured between 1949 and 1951, with stamped receiver and early type slab-sided magazine

Post-1951 production Kalashnikov AK rifle with milled receiver and bayonet attached, right side

Post-1951 production Kalashnikov AK rifle with milled receiver and bayonet, left side

Kalashnikov AK rifle with PBS silencer, as used by Soviet Spetsnaz

Kalashnikov AKM (modernized) rifle, with stamped receiver and new type of knife / bayonet

Kalashnikov AKMS – AKM with folding buttstock

Kalashnikov AKMN rifle (Modernized, with Night sight mounting bracket on the left side of receiver), with muzzle compensator installed

AKM with GP-25 40mm underbarrel grenade launcher

Caliber 7.62×39 mm
Action: Gas operated, rotating bolt with 2 lugs
Overall length: 870 mm
Barrel length: 415 mm
Weight, with empty magazine: AK 4,3 kg; AKM 3,14 kg
Magazine capacity 30 rounds (40 rounds box magazines and 75 rounds drums from RPK also may be used)
Cyclic rate of fire 600 rounds per minute

The Kalashnikov assault rifle, also known to the West as the AK-47 (Avtomat Kalashnikova – 47, Kalashnikov automatic rifle, model of 1947), and its derivatives, also known under the common name of AK, is the most prolific small arm of the 2nd half of the XX century. It had been and still is (in more or less modified form) manufactured in dozens of countries, and used in hundreds of countries and conflicts since its introduction. The total number of the AK-type rifles made worldwide during the last 60 years is estimated at 90+ millions. This is a true legendary weapon, known for its extreme ruggedness, simplicity of operation and maintenance, and unsurpassed reliability even in worst conditions possible. It is used not only as a military weapon, but also as a platform for numerous sporting civilian rifles and shotguns (see Saiga semiautomatic shotguns, for example). The AK is an amalgam of previously known features and solutions, combined in the most effective way. The effectiveness, however, depends on the criteria used to measure it, and the key criteria for any and every Soviet and Russian military arm are: Reliability, Simplicity of operation and maintenance, Suitability for mass production. There never was any significant demand for good ergonomics or superb accuracy, though.

The true story of AK began late in 1942, when Soviet troops captured several specimen of the very new German MKb.42(H) machine carbine (assault rifle), along with some 7.92 Kurz ammunition. By mid-1943 the MKb.42(H) along with US-supplied M1 carbine were evaluated by Soviet experts, and it was decided on top level that similar weapons, firing the intermediate power cartridge, must be developed for Soviet army as soon as possible. The task of initial development of new ammunition was accomplished in rather short time. By November 1943 technical specifications for the 7.62x41mm cartridge, having bottlenecked, rimless case and firing 8-gram pointed bullet, were sent out to all Soviet small arms design bureaus and organizations. By the spring of 1944, there were at least ten designs of automatic weapons in the works (not counting semi-automatic carbines that resulted in adoption of SKS and bolt-action carbines that went nowhere). In mid-1944, trials commission selected the AS-44 assault rifle, designed by Sudaev, as the overall best, and ordered a limited production run for troops trials. Some AS-44 rifles were manufactured in spring of 1945, and these were evaluated by troops in summer of 1945, just after the Victory in Europe. Troops generally liked the AS-44, as it has longer effective range compared to PPSh-41 submachine gun, and provided better accuracy in semi-automatic fire. The problem was that AS-44 was overly heavy (more than 5 kg empty), and trials commission ordered next round of development and trials, which started early in 1946.

Enter Mikhail Kalashnikov, the young sergeant of Soviet tank forces, who, after being wounded in combat in 1942, designed a prototype submachine gun while on medical leave. His first weapon was rejected on the grounds of complexity, but the designer himself was assigned to the Red Army’s Small Arms and Mortar Research & Proving ground (NIPSMVO) near the Moscow to continue his education and work on other weapons. Here Kalashnikov designed a semi-automatic carbine, heavily influenced by American M1 Garand rifle. This carbine, while not successful by itself, served as a starting point for the first Kalashnikov’s assault rifle, provisionally known as AK No.1 or AK-46. In November of 1946 the AK-46 project was chosen for prototype manufacture along with 5 other projects (out of 16 submitted to commission), and Kalashnikov was sent to the city of Kovrov (also not far from the Moscow), to manufacture his weapon at the small arms factory there. The AK-46 was gas operated, rotary bolt weapon that utilized short-stroke gas piston above the barrel, and two-part receiver with separate trigger unit housing and dual controls (separate safety and fire selector switches on the left side of the trigger unit).
In December 1946 new assault rifles were tested at NIPSMVO range, with AS-44 being used as a control (its development has ceased earlier in 1946 due to untimely death of the Sudaev, who was severely ill by the 1945). As an initial result of these tests, the AK-46 was selected for further development by trials commission, with two more weapons selected for further evolution being rifles from designers Dementiev and Bulkin. The second round of trials, which included three weapons (AK-46 by Kalashnikov, AB-46 by Bulkin and AD by Dementiev), resulted in rejection of the improved AK-46, which was inferior to other rivals in many aspects. Despite that failure, Kalashnikov, using his contacts and support from some member of trials commission (whom he knew from his earlier work at NIPSMVO in 1943-46) pursued the head of the trials commission to review the results, and finally got a green light to continue his development for next round of trials. Following the technical failure of the AK-46, Kalashnikov and his companion designer Zaitsev (who was a staff weapons designer at Kovrov plant) decided to completely rework the design, using successful technical solutions borrowed from various weapons, including direct competitors. For example, the long-stroke gas piston, attached to the bolt carrier, along with captive return spring assembly and receiver cover were apparently inspired by Bulkin’s AB-46 rifle; the idea of large clearances between bolt group and receiver walls, with minimum friction surfaces, was inspired by the Sudaev’s AS-44, the safety / dust cover lever was copied from Browning designed Remington model 8 hunting rifle etc.
It must be noted here, that such copying and borrowing of ideas was actually encouraged by the trials commission (and the whole Soviet ideology), as all intellectual property in USSR was considered to be property of ‘the people’, or the state. Thus, any state-owned intellectual property could (and must) have been used to the benefit of the people / the state by anyone. And creating a new, most effective assault rifle for the victorious Soviet army was certainly on the top of the list of things, beneficial for the Soviet state at the time.

After extensive tests, conducted in December 1947 – January 1948, which included slightly improved Dementiev KB-P-410, Bulkin TKB-415 and all-new Kalashnikov AK-47 rifles, results were somewhat inconclusive. The AK-47 was found to be most durable and reliable out of three contestants, but it also dragged behind the other two in the accuracy department, especially in full automatic (which was, and still is considered the primary mode of fire for assault rifle in Russia). In fact, the only weapon that fulfilled accuracy requirements was the Bulkin AB-47 / TKB-415, but it had certain problems with parts durability. After lengthy discussion, trials commission finally decided that the better is the enemy of the good, and it is advisable to have not-so accurate but reliable weapon now, rather than to wait indefinitely for accurate-and -reliable weapon in the future. This decision ultimately lead commission to recommend AK-47 for troops trials in November, 1947. It was decided that the production of the new weapon must be commenced at Izhevsk arms plant (now Izhevsk Machine building Plant or IzhMash in short). Kalashnikov has moved from Kovrov to Izhevsk to help with production of the new weapon, which commenced in mid-1948. Official adoption followed late in 1949, with standard nomenclature being ‘7.62mm avtomat Kalashnikova AK‘ (7.62mm automatic carbine Kalashnikov). At the same time, a folding buttstock version was adopted for airborne units use, as ‘7.62mm avtomat Kalashnikova skladnoy AKS’ (7.62mm automatic carbine Kalashnikov, folding).
It must be noted that the original design of the receiver, which was assembled from stamped steel ‘box’ with large machined steel insert pinned at the front, caused a lot of troubles at factory. The technology (equipment and labor) level of the time resulted in extremely high percentage of rejected receivers due to misformed walls, improper pinning of parts, bad geometry etc. After critical revision of the process at the factory it was calculated that it will be more economically feasible to return to the ‘old-school’ machined receivers. New, machined receiver was designed by one of factory’s staff designers, and after approval by military, it was put into production at IzhMash in 1951, under the same basic designation.

Through the following years, design of AK incorporated many minor changes and updates, but it was the experimental Korobov TKB-517 assault rifle (tested by Soviet army in mid-fifties) that spurred further development of AK. The Korobov TKB-517 assault rifle was a great deal lighter than AK, about 1/3 cheaper to manufacture, and significantly more accurate in full automatic fire. This lead the Soviet army to issue new requirements for a lighter and more effective assault rifle, which were formulated in 1955. These requirements were also complemented by requirement for a companion squad automatic / light support weapon (light machine gun in Russian nomenclature). Trials for new weapons were held in 1957-58. Kalashnikov team from Izhevsk submitted an improved AK with new type of stamped receiver and other minor improvements, which competed against a number of weapons from other design teams from the Kovrov and Tula. In technical terms, the Kalashnikov entry fared about average in these trials, with certain rival weapons proving to be more combat-effective and less expensive to make. The trials commission, however, decided again that the better is the enemy of the good, and recommended the improved AK for adoption due to its proven performance and familiarity to the industry and troops. It was officially adopted in 1959 as the AKM ( Avtomat Kalashnikova Modernizirovannyj – Kalashnikov Automatic rifle, Modified) along with companion RPK squad automatic weapon / light machine gun.

The key changes in AKM, as compared to AK, were the introduction of the stamped steel receiver instead of the milled one, and improved trigger/hammer unit, with added hammer release delay device (often incorrectly referred as a rate reducer). Other changes were the redesigned, slightly raised buttstock and the pistol grip, and the addition of the removable muzzle flip compensator. This spoon-like compensator is screwed onto the muzzle and utilized the muzzle blast to reduce muzzle climb during the automatic fire. The compensator could be replaced by the screw-on “PBS-1 noiseless firing device”, generally known as a silencer. This silencer requires a special, sub-sonic ammunition with heavier bullets to be used. Another change from AK to AKM was a slightly improved rear sight, with settings from 100 to 1000 (instead of the 800 on AK) meters. Both 800 and 1000 meters, however, are way too optimistic for any practical use, since the effective fire is limited roughly to 300-400 meters, if not less.

In the 1974, Soviet Army officially adopted the 5.45mm ammunition and the appropriately chambered AK-74 assault rifle as its new standard shoulder arm. The AKM, however, was never officially declared obsolete and removed from service, and is still in Russian army stocks. Some non-infantry units of the Russian Army are still armed with 1960s vintage AKM assault rifles. There’s also an increasing interest in the 7.62mm weapons since many troops were disappointed by the effectiveness of the 5.45mm ammo during the local conflicts in the 1990s. Some Russian special forces troops (mostly police and Internal Affairs Ministry), currently operating in Chechnya, are using the venerable 7.62mm AKM rifles.

The AK and AKM rifles were widely exported to the pro-Soviet countries and regimes all around the world. Manufacturing licenses along with all necessary technical data packages were transferred (for free or at nominal fee) to many Warsaw Pact countries (Albania, Bulgaria, China, East Germany, Hungary, North Korea, Poland, Romania, Yugoslavia). Certain ‘non-communist’, but friendly countries, such as Egypt, Finland and Iraq, also received manufacturing licenses.

At the present time, despite the world-wide proliferation of the small-bore (5.56 / 5.45mm) weapons, many companies still manufacture 7.62mm assault rifles for military or police use (for example, there’s an AK-103, made in limited numbers by the IZHMASH in Russia). Also, production of the semi-automatic only civilian AK derivatives is continued in many countries, including Russia, Bulgaria, Romania, China and others.

Technical description for the AKM assault rifle:
The AKM is a gas operated, selective fire assault rifle.

The gas operated action has a massive bolt carrier with a permanently attached long stroke gas piston. The gas chamber is located above the barrel. The bolt carrier rides on the two rails, formed on the receiver walls, with the significant clearances between the moving and stationary parts, which allows the gun to operate even when its interior is severely fouled with sand or mud. The rotating bolt has two massive lugs that lock into the receiver. Bolt is so designed that on the unlocking rotation it also makes a primary extraction movement to the fired case. This results in very positive and reliable extraction even with dirty chamber and cases. The rotation of the bolt is ensured by the curved cam track, machined in the bolt carrier, and by the appropriate stud on the bolt itself. The return spring and a spring guide are located behind the gas piston and are partially hidden in its hollow rear part when bolt is in battery. The return spring base also serves as a receiver cover lock. The cocking handle is permanently attached to the bolt carrier (in fact, it forms a single machined steel unit with carrier), and does reciprocate when gun is fired.

The receiver of the AKM is made from the stamped sheet steel, with machined steel inserts riveted into the place where required. Earliest AK-47 receivers were also made from the stamped and machined parts, riveted together, but this soon proved to be unsatisfactory, and most of the AK (made between 1951 and 1959) rifles were made with completely machined receivers. The receiver cover is a stamped sheet metal part, with stamped strengthening ribs found on the AKM covers.

The relatively simple trigger/hammer mechanism is loosely based on the 1900′s period Browning deigns (much like the most other modern assault rifles), and features a hammer with two sears – one main, mounted on the trigger extension, and one for the semi-automatic fire, that intercepts the hammer in the cocking position after the shot is fired and until the trigger is released. Additional auto sear is used to release the hammer in full auto mode. The AKM trigger unit also featured a hammer release delay device, which is served to delay the hammer release in the full auto fire by few microseconds. This does not affects the cyclic rate of fire, but allows the bolt group to settle in the forwardmost position after returning into the battery. The combined safety – fire selector switch of distinctive shape is located on the right side of the receiver. In the “Safe” position (topmost) it locks the bolt group and the trigger, and also served as a dust cover. The middle position is for automatic fire, and the bottom position is for single shots. The safety / fire selector switch is considered by many as the main drawback of the whole AK design, which is not cured in the most of derivatives until now. It is slow, uncomfortable and sometimes stiff to operate (especially when wearing gloves or mittens), and, when actuated, produces a loud and distinctive click. There’s no bolt stop device, and the bolt always goes forward when the last shot from the magazine is fired.

AKM is fed from the 30 rounds, stamped steel magazines of heavy, but robust design. Early AK magazines were of slab-sided design, but the more common AKM magazines featured additional stamped ribs on the sides. Positive magazine catch is located just ahead of the trigger guard and solidly locks the magazine into the place. Insertion and the removal of the magazine requires slight rotation of the magazine around its front top corner, that has a solid locking lug. If available and required, a 40 round box magazines of similar design, or the 75 rounds drums (both from the RPK light machine gun) can be used. Late in production plastic magazines of the distinctive reddish color were introduced.

AKM rifles were issued with wooden stocks and pistol handles. Late production AKM rifles had a plastic pistol grip instead of wooden one. The wooden buttstock has a steel buttplate with mousetrap cover, that covers the accessory container in the butt. The AK buttstock are more swept-down than the AKM ones. The folding stock version had been developed for the airborne troops and its had an underfolding steel shoulder stock. These modifications of the AK and AKM were designated the AKS and AKMS, respectively. AK were issued with the detachable knife-bayonets, and the AKM introduced a new pattern of the shorter,  multipurpose knife-bayonet, which can be used in conjunction with its sheath to form a wire-cutter. All AK and AKM rifles were issued with the canvas carrying slings.

The sights of the AKM consist of the hooded front post and the U-notch open rear. Sights are graduated from 100 to 1000 (800 on AK) meters, with an additional “fixed” battle setting that can be used for all ranges up to 300 meters.

AKM rifles also can be fitted with the 40mm GP-25 grenade launchers, that are mounted under the forend and the barrel. Grenade launchers had its own sights on the left side of the unit.

M16A1 rifle, with the forward assist, “bird cage” flash hider and the 20 rounds magazine (1967)

M16A1 rifle with 30 rounds magazine and a 40mm M203 grenade launcher attached (circa mid-1970s)

M16A2 rifle, with the heavy barrel, modified rear sights, spent case deflector, round handguards and modified pistol handle (circa mid-1980s)

M16A3 “flat top” upper receiver with the Picatinny rail and the removable carrying handle

Speak about the flexibility: just three of many dozens upper receiver options available on the market for the commercial and military AR-15 type rifles.

The history of the development, introduction and the service of the US Rifle, 5.56mm, M16, is a long and a controversial one. I’ll try to cut this story as short as possible, and will highlight only some most important periods and events. So, let’s start.

• 1948. U.S. Army’s Operations Research Office (ORO) conducts a research about small arms effectiveness. This research was completed by the early 1950 with the conclusion that the most desirable infantry small arms should be of 22 caliber, select-fire and with high velocity bullets, effective up to 300 meters or so.
• 1953 – 1957. US DOD conducts the next research, “Project SALVO”, that also lead to the desirability of .22 caliber high-velocity infantry rifle
• 1957. The US Army requests the Armalite Division of the Fairchild Aircraft Corp to develop a rifle of .22 caliber, lightweight, select-fire, and capable to penetrate the standard steel helmet at 500 meters. The Eugene Stoner, then a designer at the Armalite, began to develop this rifle, based on his earlier design, 7.62mm AR-10 battle rifle. At the same time, experts at the Sierra Bullets and the Remington, in conjunction with Armalite, began do develop a new .22 caliber cartridge, based on the .222 Remington and .222 Remington Magnum hunting cartridges. This development, initially called the .222 Remington Special, was finally released as .223 Remington (metric designation 5.56x45mm).
• 1958. Armalite delivers first new rifles, called the AR-15, to the Army for testing. Initial tests display some reliability and accuracy problems with the rifle.
• 1959. Late that year Fairchild Co, being disappointed with the development of the AR-15, sold all rights for this design to the Colt’s Patent Firearms Manufacturing Company.
• 1960. Eugene Stoner leaves the Armalite and joins the Colt. The same year Colt demonstrated the AR-15 to the US Air Force Vice Chief of Staff, Gen. LeMay. Gen. LeMay wanted to procure some 8 000 AR-15 rifles for US AF Strategic Air Command security forces to replace ageing M1 and M2 carbines.
• 1962. US DoD Advanced Research Projects Agency (ARPA) purchases 1000 AR-15 rifles from Colt and sends those rifles to the South Vietnam, for field trials. Same year brings glowing reports about the effectiveness of the new “black rifle”, used by South Vietnamese forces.
• 1963. Colt receives contracts for 85 000 rifles for US Army (designated as XM16E1) and for further 19 000 rifles for US Air Forces (M16). The US AF M16 was no more than an AR-15 rifle with appropriate markings. The XM16E1 differed from AR-15/M16 by having an additional device, the so called “forward assist”, which was used to manually push the bolt group in place in the case of jams.
• 1964. US Air Forces officially adopted new rifle as M16. Same year US Army adopted the XM16E1 as a limited standard rifle, to fill the niche between discontinued 7.62mm M14 rifle and the forthcoming SPIW system (which newer got past the prototype and trial stages).
• 1966. Colt was awarded with the contract for some 840 000 rifles for US Armed forces, worth almost $92 millions.
• 1967. US Army adopted the XM16E1 rifle as a standard “US Rifle, 5.56mm, M16A1″, on 28 February 1967.
• 1965 – 1967. Field reports from Vietnam began to look much more pessimistic. M16 rifles, issued to US troops in the Vietnam, severely jammed in combat, resulting in numerous casualties. There were some causes for malfunction. First of all, during the introduction of the new rifle and its ammunition into the service, US Army replaced originally specified Dupont IMR powder with standard ball powder, used in 7.62x51mm NATO ammunition. The ball powder produced much more fouling, that quickly jammed the actions of the M16 unless the gun was cleared well and often. This pitifully combined with the fact that the initial M16 rifles were promoted by the Colt as “low maintenance”, so, for the sake of economy, no cleaning supplies were procured for new M16 rifles, and no weapon care training was conducted fro the troops. As a result, soldiers did not knew how to clean their rifles, and had no provisions for cleaning, and thing soon turned bad. To add the trouble, the ball powders also had a different pressure curve, so they produced higher pressures at the gas port, giving the rise to the rate of fire, and, thus, decreasing accuracy and increasing parts wear.
• 1967 – 1970. The deficiencies discovered in previous years began do dissolve. 5.56mm ammunition was now loaded using different powders that produce much less residue in the gun action. The barrel, chamber and bolt of the rifles were chrome-lined to improve corrosion resistance. Cleaning kits were procured and issued to troops, and a special training programs were developed and conducted ever since. Earliest cleaning kits could be carried separate from rifle only, but since circa 1970 all M16A1 rifles were manufactured with the containment cavity in the buttstock, that held the cleaning kit. At the same time (circa 1970) the new 30 rounds magazines were introduced into service instead of the original 20 rounds ones, to equal Soviet and Chinese AK-47 assault rifles, which had 30-rounds magazines from the very beginning.
• 1977 – 1979. NATO trials lead to the adoption of the improved 5.56x45mm cartridge, developed in Belgium by FN. This cartridge, initially developed in conjunction with the FN Minimi light machine gun, featured a slightly heavier bullet with accordingly slightly lower muzzle velocity. The resulting long-range performance, however, improved due to the better ballistic coefficient of the new bullet. The SS109 required a faster rifling twist to stabilize its bullet, than the original 5.56x45mm US M193 ammunition. The M193 was used with barrels rifled with 1:12 twist (1 turn in 12 inches), and SS109 was preferred to be fired with 1:7 twist (1 turn in 7 inches). Some arms manufacturers preferred to make their guns with intermediate 1:9 rifling, which would be equally good (or bad) for both old and new loadings.
• 1981. Colt developed a variation of the M16A1, adapted for the SS109/5.56mm NATO cartridge, and submitted it to the military trials as the M16A1E1. This rifle differed from the M16A1 by having the heavier barrel with faster 1:7 rifling, a different type rear sights (adjustable for both range and windage), round handguards instead of triangular ones, and by replacing the full-auto fire mode with the burst (limited to 3 rounds per trigger pull), to preserve the ammunition.
• 1982. M16A1E1 is type-classified by US DoD as the “US Rifle, 5.56mm, M16A2″.
• 1983. US Marine Corps adopted the M61A2 rifle.
• 1985. US Army officially adopted the M16A2 as the general issue infantry rifle.
• 1988. The FN Manufacturing Co, an US subsidiary of the FN Herstal (Belgium), becomes the key contractor to US DoD for production of the M16A2 rifles. Colt continues the development and manufacture of the AR-15 / M16 type rifles only for civilian and law enforcement markets from that point.
• 1994. Adoption of the latest variations of the M16 breed. Those include: M16A3and M16A4 rifles, with “flat top” receivers, that had a Picatinny accessory rails in the place of the integral carrying handle. The rail can be used to mount detachable carrying handle with iron rear sights, or various sighting devices (Night/IR, optics etc). The M16A4 otherwise is similar to M16A2, while M16A3 has a full-auto capability instead of the 3-rounds burst. Two other newest AR-15 offsprings are the M4 and M4A1 carbines, which are described in the separate article on this site.

The M16 is still a general-issue rifle with the US Armed forces. It is also widely used by the US Law Enforcement agencies, either in military form (for example, the LAPD had some M16s, retired from Army), or in “civilian” semi-automatic only form. The AR-15 style rifles are made in the USA by at least dozen large companies, such as Armalite, Bushmaster, Colt, FN Manufacturing, Hesse, Les Baer, Olympic, Wilson Combat, and by number of smaller companies, many of which do assembly their rifles from components made by some other major manufacturers. M16-type rifles also manufactured outside of the USA, most notably in the Canada, by Diemaco Co. China also makes some AR-15 type rifles at NORINCO state factories. M16 rifles are used by many foreign military groups, most notably the British SAS, who preferred the M16 over the infamous L85A1 rifle, and by many others.

At the present time almost all initial flaws of the M16 are bugged out, and it is considered among the best assault rifles in the world. While its reliability in the harsh conditions cannot match reliability of its main rival, the Kalashnikov AK-47 and AK-74, it is still a quite reliable rifle, especially when well maintained. It is also comfortable to fire and quite accurate.

One of the key advantages of the Stoner design, that must be especially stressed, is the extreme flexibility of the construction. At the present time the interchangeable complete “uppers” are available in various barrel lengths and profiles (from 7 to 24 inches long, slim and heavy), in dozens of rifle and pistol calibers (from tiny but fast .17 Remington and up to monstrous .458 SOCOM, and from .22LR and 9mm Luger up to mighty .50AE). Special, manually single-shot uppers are commercially available in the extremely powerful .50BMG (12.7x99mm) caliber. Various “lowers” offer a broad variety of trigger units, buttstocks and other options. This advantage is viable for both military (especially Spec Ops), Law Enforcement, and civilian applications, as it allows to tailor any particular AR-15 type rifle to the current situation and tactical needs.

M16 / AR-15 Technical description

The original AR-15 rifle is a gas operated, selective fire, magazine fed weapon. Every rifle from the M16 family is generally the same, but most civilian AR-15 type rifles are semi-automatic only.

The heart of the AR-15 is the direct gas system, developed by the Eugene Stoner in the early 1950s. This system uses no conventional gas piston and rod to propel bolt group back after the shot is fired. Instead, the hot powder gases are fed from the barrel and down to the stainless steel tube into the receiver. Inside the receiver, the rear end of the gas tube enters into the “gas key”, a small attachment on the top of the bolt carrier. The hot gases, through the gas key, enter the hollow cavity inside the bolt carrier, and expands there, acting against the bolt carrier and the collar around the bolt body. The pressure of the gases causes the bolt carrier to move back against initially stationary bolt. The linear rearward movement of the carrier initially transferred into the rotation of the bolt, via the cam slot in the bolt carrier and the cam pin, attached to the bolt, that followed the slot. As soon as the bolt is rotated to unlock from the barrel, the bolt group continues its rearward travel under the inertia and the residual pressure in the barrel, extracting the spent case and compressing the buffer return spring, located in the buttstock. The forward movement of the bolt group first strips the fresh cartridge from the magazine and, on the final stage of the movement, rotates the bolt to lock into the barrel extension. The bolt has 7 radial locking lugs, eight lug is located on the extractor claw. Since the introduction of the XM16E1 rifle, the forward assist device is used on all military and most civilian AR-15 type rifles. This device consist of the spring-loaded button with internal claw, that engages the serrations on the right side of the bolt carrier to push it forward, if the pressure of the return spring is insufficient to do so (for example, due to the fouling inside the receiver or chamber). The rifle will not fire unless the bolt is locked and the bolt carrier is in its forwardmost position. The bolt carrier and the bolt itself are chrome-plated. Another feature of the AR-15 type rifles is the bolt catch device, that locks the bolt group in the open position when the last round is fired. To release the bolt group one must push the button, located at the left side of the receiver, above the magazine. The “T”-shaped cocking handle is located at the rear of the receiver, above the buttstock, and does not reciprocate when gun is fired.

The trigger/hammer group is basically similar to one, found in M1 Garand rifle, and, actually, traces its roots back to the early 1900s, when the great John M. Browning developed his famous Auto-5 semiautomatic shotgun. This basically consists of a hammer, a trigger, a disconnector, a full auto sear and some springs. The fire selector / safety switch is located at the left side of the receiver, above the pistol grip, and is easily operated by the right hand thumb. This switch has 3 positions: “safe”, “semi” (single shots), and “auto” (full automatic on M16A1 and A3) or “burst” (3 rounds bursts, on M16A2 and A4). In the latter case (on the M16A2 and A4 rifles), the trigger unit also includes the ratchet device to count the shots fired.

The ejection port is located at the right side of the receiver, and is closed by the spring-loaded dust cover, which automatically pops open when bolt carrier is pulled back. The M16A2 also featured the spent case deflector – a triangular bulb on the receiver, just behind the ejection port, that allows the gun to be safely fired left-handed.

The M16 is fed using box magazines. Earliest magazines were made from aluminum and held 20 rounds. Circa 1970 the new, 30 rounds magazines were introduced into service and these magazines are still in service now. An extremely wide variety of magazines available on the commercial marked, starting from the “US post-ban” 5 and 10 round magazines, and up to 40-rounds box, 90-rounds helical, 100-rounds dual drums (Beta-C) and 120-rounds single drums.

The receiver is made from aluminum alloy, and consists of two parts – “upper receiver” and “lower receiver” (sometimes referred simply as “upper” and “lower”). Most receivers are made from aluminum forgings by machining, but some commercially available receivers are made from aluminum castings with final drilling and machining. The upper and lower receivers are linked by two cross-pins – one at the front (pivot pin), and one at the rear, above the pistol grip (takedown pin). To field strip the AR-15, one must push the rear pin to the right as far as it will go, and then hinge the upper receiver around the front pin. This will allow the bolt group and the carrying handle to be removed from the upper receiver. For further disassembly, the front pin also must be pushed out, and the upper and lover receiver can be separated. The key benefit of this design is the great flexibility – if all components available are made to the same specifications (in most cases they are), one can easily swap various upper receivers on one lower receiver and vice versa. Since the complete “upper” module consist also of the bolt group and the barrel with the gas system, one can easily have different barrel lengths, styles (light, heavy, fluted, bull), and even calibers, for one “lower” group, that consists of the lower receiver with the trigger/hammer unit, recoil buffer, pistol grip and the buttstock.

The furniture on military rifles is made from the black plastic, hence the common name “the black rifle”. On the early AR-15 and M16A1 rifles, the handguards were of triangular cross-section, and were made from two non-interchangeable parts. On the M16A2 and latter rifles, the handguards are of round cross-section, and have two interchangeable upper-lower sections. The buttstock on the M16A2 is similar in design to one of M16A1, but slightly longer. The one disadvantage of the Stoner system is that it can not be adapted for conventional folding buttstock. Instead, if required, a telescoped stock is used, that allows to shorten the rifle when required by about the half of the length of the standard stock. M16 is usually equipped with sling, and can accept a knife – bayonet, either an old style M7, or a newer style M9. The flash hiders on the earliest AR-15s and M16s were prong-type, with three open slots, but later were replaced with “bird-cage” flash hiders with four (M16A1) or five (M16A2) slots.

Both M16A1 and M16A2 can be equipped with underbarrel 40mm M203 grenade launcher. M203 mount replaces the standard handguards on the rifle and requires a grenade launcher sight to be mounted on the carrying handle.

Standard sights of the M16A1 consist of a protected front post, mounted on the gas block, and of an aperture flip-up rear, with 2 range settings. Rear sights are mounted within the carrying handle and are adjustable for windage. The A2 style rear sight also features an flip-up, dual aperture sights, with one smaller aperture for daylight usage, and another larger aperture for low light conditions. The range adjustments are made by the rotating knob, located just under the sight. The front sight is generally the same as on the M16A1. The M16A3 and A4 rifles have detachable carrying handles with A2 sights, and the Picatinny-type MilStd rail on the top of the receiver, that can accept a wide variety of sighting devices and mounts.

The Air Force One

No matter where in the world the President travels, if he flies in an Air Force jet, the plane is called Air Force One. Technically, Air Force One is the call sign of any Air Force aircraft carrying the President. In practice, however, Air Force One is used to refer to one of two highly customized Boeing 747-200B series aircraft, which carry the tail codes 28000 and 29000. The Air Force designation for the aircraft is VC-25A.

Air Force One is one of the most recognizable symbols of the presidency, spawning countless references not just in American culture but across the world. Emblazoned with the words “United States of America,” the American flag, and the Seal of the President of the United States, it is an undeniable presence wherever it flies or docks.

Capable of refueling midair, Air Force One has unlimited range and can carry the President wherever he needs to travel. The onboard electronics are hardened to protect against an electromagnetic pulse, and Air Force One is equipped with advanced secure communications equipment, allowing the aircraft to function as a mobile command center in the event of an attack on the United States.

Inside, the President and his travel companions enjoy 4,000 square feet of floor space on three levels, including an extensive suite for the President that features a large office, lavatory, and conference room. Air Force One includes a medical suite that can function as an operating room, and a doctor is permanently on board. The plane’s two food preparation galleys can feed 100 people at a time.

Air Force One also has quarters for those who accompany the President, including senior advisors, Secret Service officers, traveling press, and other guests. Several cargo planes typically fly ahead of Air Force One to provide the President with services needed in remote locations.

Air Force One is maintained and operated by the Presidential Airlift Group, part of the White House Military Office. The Airlift Group was founded in 1944 as the Presidential Pilot Office at the direction of President Franklin D. Roosevelt. For the next 20 years, various propeller driven aircraft served the President. In 1962, President John F. Kennedy became the first President to fly in his own jet aircraft, a modified Boeing 707. Over the years, several other jet aircraft have been used, with the first of the current aircraft being delivered in 1990 during the administration of President George H. W. Bush.