97-593: The SG 550 is an assault rifle manufactured by SIG Sauer AG (formerly a division of Schweizerische Industrie Gesellschaft , now known as SIG Holding AG) in Switzerland. "SG" is an abbreviation for Sturmgewehr ("assault rifle"). The rifle is based on the earlier 5.56×45mm NATO SIG SG 540 . In 1978, the Swiss armed forces formulated requirements for a successor to the Stgw 57 battle rifle (known commercially as
194-507: A possession and acquisition licence to obtain the rifle. In 2013, a gun dealer had imported some PE 90 rifles from Switzerland and brought them to Canada for sale. After some were sold, it was alleged that the rifles in question were of a variant not allowed in Canada (PE90). Upon investigation and examination by the RCMP, this was proven inconclusive, however, the RCMP went further and decided
291-432: A 178 mm (1:7 in) twist rate is also available, to adequately stabilize the relatively long NATO L110/M856 5.56×45mm NATO tracer projectile. All rifles are test fired for accuracy and function prior to leaving the factory at the manufacturer's underground 300 m test range. Random new rifles out of production were tested on a machine rest. In a 24 single shot string starting with a cold weapon and using GP 90 ammunition,
388-514: A 178 mm (1:7 in) twist rate. The ordinance GP 90 ammunition is optimized for use with the original Swiss 254 mm (1:10 in) rifling twist rate. Due to import restrictions, the American civilian market required a partially American-made version assembled by SIG Sauer, Inc. in Exeter, New Hampshire . The SIG 556 is designed to meet these requirements. The 556 lacks full-auto capability and
485-421: A 20-round magazine is 95 g (3.4 oz) and 110 g (3.9 oz) for a 30-round magazine. A bolt hold-open device locks the bolt carrier assembly open after expending the last cartridge from the magazine and is released by lifting the bolt catch lever located on the left side of the receiver . Alternatively, a left-handed shooter may release the bolt by pulling the rubber-coated charging handle to rear
582-562: A 20-round magazine. The 5.56 mm round had to penetrate a standard U.S. helmet at 460 metres (500 yd) and retain a velocity in excess of the speed of sound, while matching or exceeding the wounding ability of the .30 Carbine cartridge. This request ultimately resulted in the development of a scaled-down version of the ArmaLite AR-10 , called the ArmaLite AR-15 rifle. However, despite overwhelming evidence that
679-560: A 3× magnified telescopic sight and an unmagnified reflex sight mounted on top of the telescopic sight. Widely distributed, it has been adopted by over 40 countries and prompted other nations to develop similar composite designs, such as the FX-05 Xiuhcoatl . Newton (unit) The newton (symbol: N ) is the unit of force in the International System of Units (SI) . Expressed in terms of SI base units , it
776-652: A Sturmgewehr was demonstrated before the People's Commissariat of Arms of the USSR . The Soviets were so impressed with the Sturmgewehr that they immediately set about developing an intermediate caliber automatic rifle of their own to replace the badly outdated Mosin–Nagant bolt-action rifles and PPSh-41 submachine guns that armed most of the Red Army. The Soviets soon developed the 7.62×39mm M43 cartridge, which
873-548: A bayonet. Further factory options for the SG 553 rifle series are an integrated receiver Picatinny rail and an adjustable butt stock. The SG 553 R is a variant chambered for the 7.62×39mm cartridge fed from AK family box magazines. There is also a .300 AAC Blackout variant of the SG 553 known as the SG 553 BK which was first shown at IWA OutdoorClassics in 2016. The SG 552-A1 is a SG 552 rifle that has been modified to function like
970-440: A button catch. A collapsible side-folding stock is also available. The stock, pistol grip , and handguards are made of a high-strength polymer , and are produced in either green or black colour options. The steel receiver housing and several other components are manufactured using stamping and welding; external steel surfaces are finished with a ceramic-reinforced enamel coat known as Ilaflon. The heavy, cold hammer-forged barrel
1067-475: A centering hole located on the front face of the rear sight assembly and a dovetail -like mounting point at the front end of the receiver. Swiss Arms (respectively Brügger & Thomet ) offer several types of quick-release scope mounts and Picatinny rails . A version of the rifle with an integral receiver-mounted Picatinny rail is also offered; in this configuration the weapon is fitted with flip-up emergency battle sights—a rear aperture sight which folds down into
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#17327901872601164-473: A diopter eyesight correction adjustment. Included with the sight is a lens hood for mounting on the ocular that reduces image quality-impairing stray light and a gray filter for glare reduction. The basic model of this optical sight was already used on the Stgw 57. The upper receiver can accept quick-detachable rails and adapters used to mount optics (STANAG 2324 compliant). The scope mounting system consists of
1261-578: A firearm must have at least the following characteristics to be considered an assault rifle: Rifles that meet most of these criteria, but not all, are not assault rifles according to the U.S. Army's definition. For example: In the United States, selective-fire rifles are legally defined as " machine guns ", and civilian ownership of those has been tightly regulated since 1934 under the National Firearms Act and since 1986 under
1358-433: A heavy, hammer-forged 650 mm (25.6 in) long barrel with a 254 mm (1:10 in) rifling twist rate (it has no flash hider) and is used exclusively with telescopic sights. The new folding stock has an adjustable cheek piece and a spacer system on the butt, the ergonomic pistol grip's angle of inclination can be regulated, the forend was shortened, and the bipod features a height and cant adjustment mechanism. This model
1455-592: A large flash suppressor had to be fitted". "Nevertheless, as a short-range weapon it is quite adequate and thus, [despite] its caliber, [the Colt Commando ] is classed as a submachine gun." Other compact assault rifles, such as the HK53 , AKS-74U and the Daewoo K1 , have been made and they have also been called submachine guns. In 1977, Austria introduced the 5.56×45mm Steyr AUG bullpup rifle, often cited as
1552-485: A lighter 125-grain bullet, which limited range but allowed for more controllable automatic fire. A smaller, lighter cartridge also allowed soldiers to carry more ammunition "to support the higher consumption rate of automatic fire". The Sturmgewehr 44 features an inexpensive, easy-to-make, stamped steel design and a 30-round detachable box magazine. This weapon was the prototype of all successful automatic rifles. Characteristically (and unlike previous rifles) it had
1649-512: A modular design with a wide range of accessories (telescoping butt-stocks, optics, bi-pods, etc.) that could be easily removed and arranged in a variety of configurations. The adoption of the M16, the H&;K33, and the 5.56×45mm cartridge inspired an international trend towards relatively small-sized, lightweight, high-velocity military service cartridges that allow a soldier to carry more ammunition for
1746-480: A pivoting trigger guard which can be folded down to the left or right side allowing for unhindered operation with winter gloves. The trigger pull is approximately 35 N (7.9 lb f ). The firearm is fed by lightweight 20-round box magazines, 30-, 10- and 5-round magazines are also available. The magazines are molded from a translucent polymer and can be locked together using studs in order to facilitate quicker reloading ( Jungle style ). The empty weight of
1843-400: A recess in the rail and a folding front blade. Both the rifle and carbine come standard with a spare magazine, sling , cleaning kit and a loading aid for rapid magazine filling. The full-sized SG 550/551 will accept SIG's 40 mm GL 5040/5140 grenade launcher (Swiss military designation: 40 mm Gewehraufsatz 97), which is mounted under the barrel via an eccentric latch and replaces
1940-427: A short distance. The SG 550 has a side-folding skeletonized buttstock (folds to the right side of the receiver) and a lightweight aluminium bipod that folds into grooves in the lower handguard. The hinged stock is firmly locked in the folded position by a socket in the butt which clips into a plastic stud on the handguard; a firm pull will release the stock which is then swung into the closed position and locked by
2037-478: A significant advantage over enemies armed primarily with bolt-action rifles. Although U.S. Army studies of World War II combat accounts had very similar results to that of the Germans and Soviets, the U.S. Army failed to recognize the importance of the assault rifle concept, and instead maintained its traditional views and preference for high-powered semi-automatic rifles. At the time, the U.S. Army believed that
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#17327901872602134-470: A small-caliber, high-velocity cartridge. Senior American commanders had faced fanatical enemies and experienced major logistical problems during World War II and the Korean War, and insisted that a single powerful .30 caliber cartridge be developed, that could be used by the new automatic rifle, and also by the new general-purpose machine gun (GPMG) in concurrent development. This culminated in
2231-439: A straight stock with the barrel under the gas cylinder to reduce the turning moment of recoil of the rifle in the shoulder and thus help reduce the tendency of shots to climb in automatic fire. The barrel and overall length were shorter than a traditional rifle and it had a pistol grip to hold the weapon more securely in automatic fire. "The principle of this weapon—the reduction of muzzle impulse to get usable automatic fire within
2328-480: Is 1 kg⋅m/s , the force that accelerates a mass of one kilogram at one metre per second squared. The unit is named after Isaac Newton in recognition of his work on classical mechanics , specifically his second law of motion . A newton is defined as 1 kg⋅m/s (it is a named derived unit defined in terms of the SI base units ). One newton is, therefore, the force needed to accelerate one kilogram of mass at
2425-475: Is a select fire rifle that uses an intermediate-rifle cartridge and a detachable magazine . Assault rifles were first put into mass production and accepted into widespread service during World War II. The first assault rifle to see major usage was the German StG 44 , a development of the earlier Mkb 42 . While immediately after World War II, NATO countries were equipped with battle rifles ,
2522-597: Is a 5.56×45mm assault rifle, designed in the early 1990s by Heckler & Koch in Germany as a replacement for the heavier G3. It was accepted into service with the Bundeswehr in 1997, replacing the G3. The G36 is gas-operated and feeds from a 30-round detachable box magazine or 100-round C-Mag drum magazine . The G36 was made with the extensive use of lightweight, corrosion-resistant synthetic materials in its design;
2619-594: Is a 7.62×51mm, selective fire, automatic rifle produced by the Belgian armaments manufacturer Fabrique Nationale de Herstal (FN). During the Cold War it was adopted by many North Atlantic Treaty Organization (NATO) countries, most notably with the British Commonwealth as the semi-automatic L1A1 . It is one of the most widely used rifles in history, having been used by more than 90 countries. The FAL
2716-657: Is generally attributed to Adolf Hitler , who used the German word Sturmgewehr (which translates to "assault rifle") as the new name for the MP 43 ( Maschinenpistole ) , subsequently known as the Sturmgewehr 44 . Allied propaganda suggested that the name was chosen for propaganda purposes, but the main purpose was to differentiate the Sturmgewehr from German submachine guns such as the MP 40 . It has been suggested, however, that
2813-399: Is hammer-fired and has a trigger mechanism with an ambidextrous safety and fire selector switch that has 4 settings: "S"—safe, "1"—single fire, "3"—3-round burst and "20"—fully automatic fire . The 3-round burst mode "3" and the fully automatic "20" position can be disabled by a rotating safety guard to avert accidentally activating the continuous fire mode. The trigger is enclosed in
2910-412: Is named after Isaac Newton . As with every SI unit named for a person, its symbol starts with an upper case letter (N), but when written in full, it follows the rules for capitalisation of a common noun ; i.e., newton becomes capitalised at the beginning of a sentence and in titles but is otherwise in lower case. The connection to Newton comes from Newton's second law of motion , which states that
3007-449: Is no longer in production. The SG 550/551/552/553 are also available in semi-automatic only configurations, intended for the civilian shooting market. Among these variants are the SG 550/551/552 SP , PE 90 and SIG Sport rifles. The SG 550 series is available with either 178 mm or 254 mm (1:7 and 1:10 in) twist rate barrels. Rifles designated SG 55x-1 have a 254 mm (1:10 in) twist rate, while models marked SG 55x-2 have
SIG SG 550 - Misplaced Pages Continue
3104-566: Is screwed into the receiver and is equipped with a slotted "bird cage" type flash suppressor that is also used to launch rifle grenades (using standard, live ammunition ) or attach a knife bayonet (the bayonet is supported by a lug located at the base of the gas block). The rifled barrel has 6 right-hand grooves and the Swiss Army specification 254 mm (1:10 in) rifling twist rate is optimized for Swiss military GP 90 ammunition. An export-oriented 5.56×45mm NATO barrel configuration with
3201-603: Is the Swiss equivalent to NATO 's standard 5.56×45mm cartridge. In February 1983, the decision to adopt the SG 541 was publicly announced (the designation of the rifle was changed in October of the following year to SG 550, while the carbine version became known as the SG 551 ). Production began in 1986 and four years later the rifle was officially accepted into service in 1990, hence the military designation Stgw 90. Over 600,000 rifles have been delivered since then and production for
3298-474: The Heereswaffenamt was responsible for the name Sturmgewehr , and Hitler had no input besides signing the production order . Furthermore, Hitler was initially opposed to the idea of a new infantry rifle, as Germany lacked the industrial capacity to replace the 12,000,000 Karabiner 98k rifles already in service, only changing his mind once he saw it first-hand. The StG 44 is generally considered
3395-508: The 7.62×39mm cartridge and using AK -pattern box magazines was introduced. The first generation of SIG 556R rifles had a number of performance issues that were later resolved in later production runs of the SIG 556R. In January 2014, SIG introduced the 556xi series rifles as an improvement to the 556 and 556R series rifles. As of May 2017, SIG has discontinued the SIG 556, SIG 556R, and 556xi series of rifles and no longer displays those models on
3492-493: The Firearm Owners Protection Act . However, the term "assault rifle" is often conflated with " assault weapon ", a U.S. legal category with varying definitions which includes many semi-automatic weapons. This use has been described as incorrect and a misapplication of the term. The 1890s Cei-Rigotti prototype was built to fire the fully powered 7.65×53mm Mauser and the weaker 6.5×52mm Carcano , it
3589-660: The HK G3 or HK MP5 . The sights consist of a rear, rotating diopter drum soldered to the receiver and a hooded front post installed in the gas block. The rear sight has an open notch setting marked "1" designed for immediate firing up to 100 m but also contains apertures with settings "2", "3" and "4" corresponding to 200, 300 and 400 m firing ranges. The 400 m setting has a removable iris for sportive shooting. The sights are adjustable via micrometer screws with windage and elevation increments of 0.15 mil (≈0.52 moa ), or 15 mm (0.6 in) at 100 m. For night use,
3686-772: The Russian Empire and later in the Russian Soviet Federative Socialist Republic . A total of 3,200 Fedorov rifles were manufactured between 1915 and 1924 in the city of Kovrov ; the vast majority of them were made after 1920. The weapon saw limited combat in World War I , but was used more substantially in the Russian Civil War and in the Winter War . Some consider it to be an "early predecessor" or "ancestor" of
3783-421: The SG 552 LB incorporates a 346 mm (13.6 in) barrel with provision to fire rifle grenades and support a bayonet. The SG 552 models were discontinued in 2008 and replaced by the SG 553. Upgrade part kits are available to convert a SG 552 in to a SG 553. The SG 553 is an improved version of the SG 552 and was released in 2008. Even though it mostly resembles the SG 552, the SG 553 has one key advantage,
3880-572: The Type 56 ). As a result, more AK-type weapons have been produced than all other assault rifles combined. As of 2004, "of the estimated 500 million firearms worldwide, approximately 100 million belong to the Kalashnikov family, three-quarters of which are AK-47s." The U.S. Army was influenced by combat experience with semi-automatic weapons such as the M1 Garand and M1 Carbine , which enjoyed
3977-520: The 1960s other countries would follow the Americans' lead and begin to develop 5.56×45mm assault rifles, most notably Germany with the Heckler & Koch HK33 . The HK33 was essentially a smaller 5.56mm version of the 7.62×51mm Heckler & Koch G3 rifle. As one of the first 5.56mm assault rifles on the market, it would go on to become one of the most widely distributed assault rifles. The HK33 featured
SIG SG 550 - Misplaced Pages Continue
4074-508: The 1970s, Finland, Israel, and South Africa introduced AK type assault rifles in 5.56×45mm. Sweden began the transition with trails in 1981 and full adaptation in 1986. During the 1990s, Russia developed the AK-101 in 5.56×45mm NATO for the world export market. In addition, Bulgaria, Czechoslovakia, Hungary, Poland and Yugoslavia (i.e., Serbia) have also rechambered their locally produced assault rifles to 5.56mm NATO. The AK-74 assault rifle
4171-543: The 5.56×45mm FAMAS bullpup rifle. In 1985, the British introduced the 5.56×45mm L85 bullpup rifle. In the late 1990s, Israel introduced the 5.56mm NATO Tavor TAR-21 . In 1997, China adopted the QBZ-95 in the new 5.8×42mm cartridge, which they claim is superior to both the 5.56×45mm and the 5.45×39mm. By the turn of the century, the bullpup assault rifle design had achieved worldwide acceptance. The Heckler & Koch G36
4268-467: The 5.56×45mm NATO cartridge has become not only the NATO standard but "the standard assault-rifle cartridge in much of the world". It also led to the development of small-caliber high-velocity service rifles by every major army in the world, including the USSR and People's Republic of China. Today, many small arms experts consider the M16 the standard by which all other assault rifles are judged. During
4365-416: The 5.56×45mm cartridge. This shift represented a change in the philosophy of the military's long-held position about caliber size. By the middle of the 1970s, other armies were looking at assault rifle-type weapons. A NATO standardization effort soon started and tests of various rounds were carried out starting in 1977. The U.S. offered the 5.56×45mm M193 round, but there were concerns about its penetration in
4462-451: The 552-2P) carbine was released in July 1998. It has a shorter 226 mm (8.9 in) barrel (with an open, 3-prong flash suppressor) and gas tube, ventilated handguards and a redesigned bolt carrier group that was integrated with the piston rod to form a single moving assembly. The SG 552 series rifles have a 360 mm (14.2 in) long sight radius. The return mechanism has been moved to
4559-627: The AK-47 and the M14 ("assault rifle" vs "battle rifle") came in the early part of the Vietnam War . Battlefield reports indicated that the M14 was uncontrollable in full-auto and that soldiers could not carry enough ammunition to maintain fire superiority over the AK-47. And, while the M2 Carbine offered a high rate of fire, it was under-powered and ultimately outclassed by the AK-47. A replacement
4656-547: The AR-15 could bring more firepower to bear than the M14, the Army opposed the adoption of the new rifle. In January 1963, Secretary of Defense Robert McNamara concluded that the AR-15 was the superior weapon system and ordered a halt to M14 production. At the time, the AR-15 was the only rifle available that could fulfill the requirement of a universal infantry weapon for issue to all services. After modifications (most notably,
4753-576: The American M9 . The SG 551 carbine has a short pattern 363 mm (14.3 in) barrel, gas tube and piston compared to the SG 550. The SG 551 series rifles have a 466 mm (18.3 in) long sight radius. The handguards were also changed and the bipod removed. The SG 551 cannot be used with a bayonet or fire rifle grenades. The SG 551 comes in several specialized variants designed for use with security and special forces. Among those variants are: The compact SG 552 Commando (full designation as
4850-522: The M1 Garand proved disappointing. During the Korean War , the select-fire M2 Carbine largely replaced the submachine gun in U.S. service and became the most widely used Carbine variant. Combat experience suggested that the .30 Carbine round was under-powered. American weapons designers reached the same conclusion as the German and Soviet ones: an intermediate round was necessary, and recommended
4947-694: The Mulhouse facility between 1946 and 1949. Vorgrimler later went to work at CETME in Spain and developed the line of CETME automatic rifles based on his improved StG 45 design. Germany eventually purchased the license for the CETME design and manufactured the Heckler & Koch G3 as well as an entire line of weapons built on the same system, one of the most famous being the MP5 SMG . The first confrontations between
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#17327901872605044-411: The R 50 or 50% windage and elevation dispersion of any individual weapon must have been within an 11 cm (4.3 in) group at 300 m, the 50% windage and elevation dispersion must have averaged 7 cm (2.8 in). The employed circular error probable method cannot be converted and is not comparable to US military methods for determining rifle accuracy. When the R 50 results are doubled
5141-616: The Red Army's new mobile warfare doctrines. In the 1960s, the Soviets introduced the RPK light machine gun , itself an AK-47 type weapon with a bipod , a stronger receiver, and a longer, heavier barrel that would eventually replace the RPD light machine gun. The AK-47 was widely supplied or sold to nations allied with the USSR, and the blueprints were shared with several friendly nations (the People's Republic of China standing out among these with
5238-459: The SG 510) using the 7.5×55mm GP 11 cartridge . Emphasis was placed on modularity ; the weapon family was to include several variants of the base design, including a compact carbine that would be issued to rear-echelon and support troops, command staff, vehicle crews, special forces personnel and paratroopers . Another aim was to reduce the overall weight of the rifle while retaining comparable or improved accuracy out to 300 m. The solicitation
5335-413: The SG 550 is equipped with a Kern 4×24 telescopic sight on a quick-detachable mount. The sight weighs 730 g (26 oz) and includes a variety of features, such as STANAG 2324/MIL-STD-1913 compliant mounting components, a Bullet Drop Compensation (BDC) elevation adjustment knob for ranges from 100 to 600 m, a tritium-illuminated reticle that enables target acquisition in low-light conditions and
5432-487: The SG 553. The modifications are available as a conversion kit that includes a new bolt carrier, charging handle, recoil spring and gas tube. Another member of the SG 550 family is the SG 550-1 Sniper variant designed at the request of the Swiss Police. Introduced in 1988, This accurized rifle has a refined two-stage trigger (the pull force was reduced from 35 N (7.9 lb f ) to 15 N (3.4 lb f ),
5529-458: The SI definition of the newton: 1 kg⋅m/s . At average gravity on Earth (conventionally, g n {\displaystyle g_{\text{n}}} = 9.806 65 m/s ), a kilogram mass exerts a force of about 9.81 N. Large forces may be expressed in kilonewtons (kN), where 1 kN = 1000 N . For example, the tractive effort of a Class Y steam train locomotive and
5626-541: The Spanish state-owned design and development agency CETME ( Centro de Estudios Técnicos de Materiales Especiales ). The rifle proved successful in the export market, being adopted by the armed forces of over 60 countries. After World War II, German technicians involved in developing the Sturmgewehr 45 , continued their research in France at CEAM. The StG 45 mechanism was modified by Ludwig Vorgrimler and Theodor Löffler at
5723-495: The Sturmgewehr 44 was "intended in a general way to serve the same purpose as the U.S. carbine" and was in many ways inferior to the M1 carbine, and was of "little importance". After World War II, the United States military started looking for a single automatic rifle to replace the M1 Garand, M1/M2 Carbines, M1918 Browning Automatic Rifle , M3 "Grease Gun" and Thompson submachine gun . Early experiments with select-fire versions of
5820-465: The U.S, a variety of semi-automatic SwissArms firearms are available for sale. Due to U.S. import regulations, they are imported as a pistol. On 27 February 2014, the Canadian semi-automatic "Classic Green" sporting rifle, also known as the "Swiss Arms PE 90", was re-classified as a "prohibited weapon". The rifle had been popular with hunters and gun enthusiasts, who until February 2014, only required
5917-432: The actual ranges of combat—was probably the most important advance in small arms since the invention of smokeless powder ." Like the Germans, the Soviets were influenced by experience showing that most combat engagements occur within 400 metres (1,300 ft) and that their soldiers were consistently outgunned by heavily armed German troops, especially those armed with Sturmgewehr 44 assault rifles. On July 15, 1943,
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#17327901872606014-455: The amount needed to accelerate one kilogram of mass at the rate of one metre per second squared. In 1948, the 9th CGPM Resolution 7 adopted the name newton for this force. The MKS system then became the blueprint for today's SI system of units. The newton thus became the standard unit of force in the Système international d'unités (SI), or International System of Units . The newton
6111-502: The charging handle was re-located from under the carrying handle like it was on AR-10 to the rear of the receiver), the newly redesigned rifle was subsequently adopted as the M16 Rifle. "(The M16) was much lighter compared to the M14 it replaced, ultimately allowing soldiers to carry more ammunition. The air-cooled, gas-operated, magazine-fed assault rifle was made of steel, aluminum alloy and composite plastics, truly cutting-edge for
6208-523: The dedicated "1" notch setting in the rear sight drum is provided with two self-luminous tritium-powered inserts fitted laterally on each side of the notch and additionally in a flip-up post attached to the foresight. When firing rifle grenades the front sight hood is aligned with the uppermost edge of the grenade's warhead, this provides an estimated point of impact up to 75 m. The rifle grenades intended for this purpose were FN/Luchaire Type 58-N bullet-though anti-tank grenades . For designated marksman use,
6305-674: The development of the 7.62×51mm NATO cartridge and the M14 rifle which was basically an improved select-fire M1 Garand with a 20-round magazine. The U.S. also adopted the M60 GPMG , which replaced the M1919 Browning machine gun in major combat roles. Its NATO partners adopted the FN FAL and Heckler & Koch G3 rifles, as well as the FN MAG and Rheinmetall MG3 GPMGs. The FN FAL
6402-534: The development of the M16 rifle during the Vietnam War prompted the adoption of assault rifles by the rest of NATO. By the end of the 20th century, assault rifles had become the standard weapon in most of the world's armies, replacing full-powered rifles and submachine guns in most roles. The two most successful modern assault rifles are the AK-47 and the M16 designs and their derivatives. The term assault rifle
6499-425: The face of the wider introduction of body armor . In the end the Belgian 5.56×45mm SS109 round was chosen ( STANAG 4172) in October 1980. The SS109 round was based on the U.S. cartridge but included a new stronger, heavier, 62-grain bullet design, with better long-range performance and improved penetration (specifically, to consistently penetrate the side of a steel helmet at 600 metres or 2,000 feet). Also during
6596-450: The first selective fire military rifle to popularize the assault rifle concept. Today, the term assault rifle is used to define firearms sharing the same basic characteristics as the StG 44. The U.S. Army defines assault rifles as "short, compact, selective-fire weapons that fire a cartridge intermediate in power between submachine gun and rifle cartridges." In this strict definition,
6693-475: The first successful bullpup rifle , finding service with the armed forces of over twenty countries. It was highly advanced for the 1970s, combining in the same weapon the bullpup configuration, a polymer housing, dual vertical grips, an optical sight as standard, and a modular design. Highly reliable, light, and accurate, the Steyr AUG showed clearly the potential of the bullpup layout. In 1978, France introduced
6790-471: The force exerted on an object is directly proportional to the acceleration hence acquired by that object, thus: F = m a , {\displaystyle F=ma,} where m {\displaystyle m} represents the mass of the object undergoing an acceleration a {\displaystyle a} . When using the SI unit of mass, the kilogram (kg), and SI units for distance metre (m), and time, second (s) we arrive at
6887-573: The hit probability increases to 93.7%. The gas system's components are made of stainless steel . The barrel, bolt, bolt carrier, and firing pin are all made with steel that has been gas nitrided , hardened and tempered. The bolt and carrier, along with most other components internal to the receiver undergo a phosphating process. The SG 550 series rifles have a 540 mm (21.3 in) long sight radius and are equipped with iron sights adjustable for both windage and elevation. The sights are similar to those on some Heckler & Koch weapons, such as
6984-601: The lower handguard . The grenade launcher is a single-shot breech-loaded weapon that is supplied with a leaf sight that attaches to the rifle's rear sight base and enables accurate firing out to 200 m. The lightweight aluminium launcher weighs 1.7 kg (3.7 lb) unloaded, and is operated independently of the rifle. It can use a wide array of 40×46mm grenades, including extended range high-pressure types and non-lethal baton or anti-riot projectiles. The compact SG 552/553 can be fitted with smaller GL 5340 underbarrel grenade launcher. An Stgw 90 bayonet can also be mounted to
7081-530: The matter through the legal system. On 31 July 2015, the Canadian government overturned the reclassification and returned the Swiss rifles to the original classifications. On 1 May 2020, in the wake of the Nova Scotia attacks , the rifles were again reclassified as Prohibited Firearms via Order in Council . Grupo de Especial de Seguridad, Policia de Mendoza Assault rifle An assault rifle
7178-488: The military has now ceased. The SG 550 is a selective-fire 5.56×45mm NATO assault rifle firing from a closed bolt . It has a gas-actuated piston-driven long-stroke operating system derived from the SIG SG 540 series of rifles, which uses burnt powder gases vented through a port in the barrel to power the weapon's moving parts. Once inside the gas cylinder, propellant gases pass through an L-shaped channel machined in
7275-404: The modern assault rifle. The Germans were the first to pioneer the assault rifle concept during World War II, based upon research that showed that most firefights happen within 400 metres (1,300 ft) and that contemporary rifles were overpowered for most small arms combat. They would soon develop a select-fire intermediate powered rifle combining the firepower of a submachine gun with
7372-443: The overall length is 940 mm (37.0 in). One difference is a new aluminum lower receiver that accepts M16 STANAG magazines and an M4 telescoping buttstock . The barrel's twist rate is 178 mm (1:7 in). There are many variants of this rifle offered for sale. The first variant was sold with an aluminum Picatinny rail on the upper receiver and a series of plastic rails on the handguard. The market pushed SIG to produce
7469-525: The piston head and are directed forward towards the gas valve. The pressure build-up in front of the piston head pushes the piston and bolt carrier rearward. As the piston is driven back, the gas port and the L-shaped channel move out of alignment, cutting off the supply of gas to the cylinder. Surplus gas and powder residues are evacuated through an exhaust port in the gas cylinder. The manually adjustable gas valve has two settings, one for normal operation, and
7566-419: The products section of their website. The SIG 522LR is a .22 -caliber sporting rifle styled after the SG 551. It uses a simple blowback semi-automatic operating system and its barrel has a 406 mm (1:16 in) twist rate. Due to its operating principle, the rifle has no mechanical commonality with other SG 550 variants. The SIG 522 accepts commonly available AR-style .22-caliber conversion magazines. In
7663-409: The range and accuracy of a rifle. The result was the Sturmgewehr 44, an improvement of the earlier Maschinenkarabiner 42(H) , and approximately half a million Sturmgewehrs were produced by the war's end. It fired a new and revolutionary intermediate powered cartridge, the 7.92×33mm Kurz. This new cartridge was developed by shortening the standard 7.92×57mm Mauser round and giving it
7760-536: The rate of one metre per second squared in the direction of the applied force. The units "metre per second squared" can be understood as measuring a rate of change in velocity per unit of time, i.e. an increase in velocity by one metre per second every second. In 1946, the General Conference on Weights and Measures (CGPM) Resolution 2 standardized the unit of force in the MKS system of units to be
7857-406: The rear of the receiver housing and its recoil spring is guided in a way analogous to that of the AK-47 : on a steel guide rod (later models feature a polymer guide rod) resting against the lower receiver's rear surface under tension of the compressed recoil spring. Like the SG 550/551, this model can accept rails and accessories enabling the use of optics. A long barrel version of the SG 552 known as
7954-495: The receiver housing, stock, trigger group (including the fire control selector and firing mechanism parts), magazine well, handguard and carrying handle are all made of a carbon fiber -reinforced polyamide . The receiver has an integrated steel barrel trunnion (with locking recesses) and a nylon 66 steel reinforced receiver. The standard Bundeswehr versions of the G36 are equipped with a unique ZF 3×4° dual optical sight that combines
8051-458: The recoil spring is now wrapped around the piston rod as in the SG 550/551 models, which address several reliability issues encountered in the SG 552 and also allows the usage of the standard SG 550/551 charging handle. The SG 553 series rifles have a 339 mm (13.3 in) long sight radius. A long barrel version of the SG 553 known as the SG 553 LB incorporates a 347 mm (13.7 in) barrel with provision to fire rifle grenades and support
8148-489: The rifle with the slimmer profile 551-type handguards and a hooded front sight; this version is marketed as the SIG 556 Classic . Several folding stock models have been released as well as variants with railed forend combinations. Another variant is the SIG 556 DMR featuring a 18 in (457.2 mm) barrel. SIG P556 pistol variants with 10-inch barrels are also available. In 2012 the SIG 556 R or SIG 556 Russian chambered for
8245-459: The rifle. The bayonet has an overall length of 310 mm and a muzzle ring diameter of 22 mm. The 177 mm long blade is single-edged and it has no fuller . The bayonets are manufactured exclusively for the Swiss Army by Victorinox and in the past by Wenger until Victorinox acquired Wenger in 2005. With a proper lug adaptor, the rifle will also accept a NATO-pattern KCB-77 (made originally by Carl Eickhorn of Solingen , West Germany ) or
8342-423: The same weight compared to the larger and heavier 7.62×51mm NATO cartridge. The 5.56mm cartridge is also much easier to shoot. In 1961 marksmanship testing, the U.S. Army found that 43% of AR-15 shooters achieved Expert, while only 22% of M-14 rifle shooters did so. Also, a lower recoil impulse, allows for more controllable automatic weapons fire. In March 1970, the U.S. recommended that all NATO forces adopt
8439-408: The second setting for use in the presence of heavy fouling or icing. The rotary bolt locking mechanism consists of two steel locking lugs that engage locking recesses in the breech, and is identical to that used in the SG 540. A spring-loaded extractor is incorporated into the bolt while a fixed protrusion on one of the receiver's internal guide rails ejects the spent cartridge casings. The rifle
8536-471: The time. Designed with full and semi-automatic capabilities, the weapon initially did not respond well to wet and dirty conditions, sometimes even jamming in combat. After a few minor modifications, the weapon gained in popularity among troops on the battlefield." Despite its early failures, the M16 proved to be a revolutionary design and stands as the longest continuously serving rifle in American military history. It has been adopted by many U.S. allies and
8633-452: The versions in Canada were too close to the PE90 and reclassified the rifles and declared the entire model line prohibited, with possible confiscation for destruction. This caused outrage amongst owners and lobbyists, who felt that the RCMP exceeded their authority, and that such policy changes should be enacted by legislation. The National Firearms Association of Canada considered pursuit of
8730-532: The worldwide trend toward small caliber, high-velocity cartridges. Following the adoption of the M16, carbine variants were also adopted for close quarters operations. The AR-15 family of weapons served through the Vietnam War. However, these compact assault rifles had design issues, as "the barrel length was halved" to 10 inches (250 mm) which "upset the ballistics", reducing its range and accuracy and leading "to considerable muzzle flash and blast, so that
8827-521: Was a Soviet answer to the U.S. M16. The Soviet military realized that the M16 had better range and accuracy over the AKM, and that its lighter cartridge allowed soldiers to carry more ammunition. Therefore, in 1967, the USSR issued an official requirement to replace the AKM and the 7.62×39mm cartridge. They soon began to develop the AK-74 and the 5.45×39mm cartridge. AK-74 production began in 1974, and it
8924-638: Was first used in the semi-automatic SKS carbine and the RPD light machine gun . Hugo Schmeisser , the designer of the Sturmgewehr, was captured after World War II, and, likely, helped develop the AK-47 assault rifle, which would quickly replace the SKS and Mosin in Soviet service. The AK-47 was finalized, adopted and entered widespread service in the Soviet army in the early 1950s. Its firepower, ease of use, low production costs, and reliability were perfectly suited for
9021-483: Was narrowed down to two designs: the W+F C42 (developed by the state-owned Waffenfabrik Bern , using both 6.45×48mm and 5.56×45mm cartridges) and the SG 541 (developed by SIG using the SG 540 as the basis for the SG 541 prototype). In 1981, the experimental 6.45mm GP 80 cartridge was rejected in favor of the more conventional SIG 5.6×45mm Gw Pat 90 round (with a 4.1 g, tombac -jacketed, lead core projectile) that
9118-403: Was needed: A medium between the traditional preference for high-powered rifles such as the M14, and the lightweight firepower of the M2 Carbine. As a result, the Army was forced to reconsider a 1957 request by General Willard G. Wyman, commander of the U.S. Continental Army Command (CONARC) to develop a .223 caliber (5.56 mm) select-fire rifle weighing 2.7 kg (6 lb) when loaded with
9215-519: Was predominantly chambered for the 7.62mm NATO round, and because of its prevalence and widespread use among the armed forces of many western nations during the Cold War, it was nicknamed "The right arm of the Free World ". The Heckler & Koch G3 is a 7.62×51mm, selective fire, automatic rifle produced by the German armament manufacturer Heckler & Koch GmbH (H&K) in collaboration with
9312-444: Was somewhat of a predecessor. However, it had its magazine fixed. The Fedorov Avtomat (also anglicized as Federov, Russian: Автома́т Фёдорова , romanized : Avtomát Fyódorova , IPA: [ɐftɐˈmat ˈfʲɵdərəvə] , lit. 'Fyodorov's automatic rifle') is a select-fire infantry rifle and also one of the world's first operational automatic rifles, designed by Vladimir Grigoryevich Fyodorov in 1915 and produced in
9409-603: Was unveiled in 1977, when it was carried by Soviet parachute troops during the annual Red Square parade . It would soon replace the AKM and become the standard Soviet infantry rifle. In 1979, the AK-74 saw combat for the first time in Afghanistan , where the lethality of the 5.45mm rounds led to the Mujahadeen dubbing them "poison bullets". The adoption of the 5.56mm NATO and the Russian 5.45×39mm cartridges cemented
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