Question: Which riffle on which SIG SG 550 is based is a 5.56×45mm NATO assault rifle developed in the early 1970s by Schweizerische Industrie Gesellschaft?

full_context: Document 1: MG 51: The 7.5 mm Maschinengewehr 1951 or Mg 51 is a general-purpose machine gun manufactured by W+F of Switzerland. The weapon was introduced into Swiss service when the Swiss Army initiated a competition for a new service machine gun to replace the MG 11 heavy machine gun and the Furrer M25 light machine gun adopted in 1911 and 1925 respectively.
Document 2: Knight's Armament Company SR-47: The SR-47 is a modern rifle based on the AR-15 family of rifles created by Knight's Armament Company for USSOCOM. Unlike the majority of ArmaLite-type guns, the SR-47 is essentially an AR-15 that fires the Soviet 7.62×39mm round from AK-47 magazines, which explains the "47" in the gun's name. The rifle was created after soldiers on long missions in Operation Enduring Freedom complained of running out of 5.56×45mm NATO ammunition for their M4 carbines but having plenty of captured AK-47 magazines. The SR-47 is basically an M4 that will accept standard AK-47 magazines rather than NATO STANAG M16/M4 mags, along with other minor modifications common to KAC's designs.
Document 3: Steyr SSG 04: The Steyr SSG 04 (German: Scharfschützengewehr 2004, English: Sniper Rifle 04) is a modern bolt action sniper rifle developed and produced by Steyr Mannlicher in Austria, as a complement to Steyr's SSG 69, using the same Safe Bolt System (SBS) action developed for Steyr's hunting rifles. It is also the basis for the Steyr SSG 08 and Steyr SSG Carbon.
Document 4: FM57 rifle: The FM1957 is a Swedish prototype battle rifle based on the Ljungman Ag m/42 semi-automatic rifle. Along with the FN FAL, M14 rifle, Rk 60 and GRAM 63 battle rifle, it was in competition to replace the bolt action Mausers and the Ag m/42 rifles in Swedish service during the early 1960s but lost over the Heckler & Koch G3 (license built as the Ak 4 in Sweden). The FM57 therefore never entered serial production. The rifle was built in two calibers: the 6.5×55mm (standard in the Swedish Armed Forces at the time) and the 7.62×51mm NATO (which later replaced the 6.5 mm cartridge in Swedish service).
Document 5: Steyr SSG 69: The SSG 69 ("Scharfschützengewehr 69" = Sniper Rifle 69) is a bolt-action sniper rifle produced by Steyr Mannlicher that serves as the standard sniper rifle for the Austrian Army.
Document 6: STG-556: The STG-556 is a Steyr AUG A1 a clone manufactured by Microtech Small Arms Research (MSAR). It was introduced at the 2007 SHOT Show. The STG-556's working system features a bolt release as seen on the M16 rifle; otherwise, the STG-556 retains the features similar to the Steyr AUG, such as having the quick-change barrel option and the ability to change which side the weapon ejects from by changing the bolt out for a right or left side bolt respectively. There is some parts interchangeability but the rifle is not a true clone. The STG-556 ships standard with right side ejector. The STG-556 is unable to use M16-style magazines or STANAG NATO standard magazines; they use versions of a proprietary MSAR magazine resembling the Steyr mags. The current production XM-17 E4 use STANAG magazines. The STG-556 is a short-stoke gas piston. The STG-556 rifle can be converted from either having a telescopic sight or a MIL-STD-1913 rail. It is available in civilian (semi-automatic only) and military/law enforcement (select-fire) variants.
Document 7: Sturmgewehr 52: The Sturmgewehr 52 (STG-52) was a battle rifle manufactured by the government-owned W+F Bern of Switzerland. It was chambered in the 7.5mm Kurzpatrone cartridge and later the 7.5mm Swiss service round as the Sturmgewehr 54, which was fed from the right-hand side. The Sturmgewehr 52 was heavily patterned after the German FG 42 as it was fed from the side from a 30- or 40-round magazine and was also fitted with a muzzle attachment capable of launching rifle grenades.
Document 8: Steyr SSG 08: The Steyr SSG 08 (German: Scharfschützengewehr 2008, English: Sniper Rifle 08) is a modern bolt-action sniper rifle developed and produced by Steyr Mannlicher in Austria. The rifle is a further evolution of the SSG 04 sniper rifle, also developed and produced by Steyr.
Document 9: Heckler &amp; Koch MP7: The Heckler & Koch MP7 "(Machine Pistol 7)" is a German Personal Defence Weapon (PDW) designed and manufactured by Heckler & Koch (H&K) and chambered for the HK 4.6×30mm cartridge. It was designed with the new cartridge to meet NATO requirements published in 1989, as these requirements call for a personal defense weapon (PDW) class firearm, with a greater ability to penetrate body armor than current weapons limited to conventional pistol cartridges. The MP7 went into production in 2001. It is a direct rival to the FN P90, also developed in response to NATO's requirement. The weapon has been revised since its introduction and the latest production variants are the MP7A1 and MP7A2.<ref name="Heckler & Koch HK MP7 Submachine Gun / Machine Pistol July 30, 2012"> </ref>
Document 10: SIG Sauer: There are two SIG Sauer companies. The original company, SIG Sauer GmbH, is a Swiss-German firearms manufacturer and exporter, formed in 1976 as a partnership between Schweizerische Industrie Gesellschaft (SIG) of Switzerland and J.P. Sauer & Sohn of Germany. SIG (now known as SIG Holding, AG) no longer has any firearms business. Their firearms subsidiary, Swiss Arms AG, was sold to (L&O Holding) of Emsdetten, Germany and was renamed Swiss Arms. L&O Holding is currently the parent company of SIG Sauer GmbH.
Document 11: SIG SG 530: The SIG SG 530 was a Swiss assault rifle developed in the 1960s by Schweizerische Industrie Gesellschaft (SIG) to take the then-new 5.56×45mm NATO round.<ref name="Swissrifles-SIG SG530/1"> </ref>
Document 12: SIG SG 550: The SG 550 is an assault rifle manufactured by Swiss Arms AG (formerly a division of Schweizerische Industrie Gesellschaft now known as Sig Holding AG) of Neuhausen, Switzerland. "SG" is an abbreviation for "Sturmgewehr", or "assault rifle". The rifle is based on the earlier 5.56mm SG 540 and is also known as the Fass 90 ("Fusil d'assaut" 90/"Fucile d'assalto" 90) in French/Italian or Stgw 90 in German ("Sturmgewehr" 90).<ref name="SwissArms-SG550/PE90"> </ref>
Document 13: SIG SG 540: The SG 540 is a 5.56×45mm NATO assault rifle developed in the early 1970s by Schweizerische Industrie Gesellschaft (SIG, currently SAN Swiss Arms AG) based out of Neuhausen, Switzerland as a private venture primarily destined for export markets and as a potential replacement for the 7.5×55mm Swiss SG 510 automatic rifle known as the Stgw 57 in Swiss service.
Document 14: SIG MG 710-3: The SIG MG 710-3 is a Swiss 7.62 mm general-purpose machine gun (GPMG) designed and manufactured by SIG - Schweizerische Industrie Gesellschaft (currently Swiss Arms AG). The weapon was developed as a commercial venture primarily for export, since the Swiss Army had already adopted the 7.5 mm MG 51 GPMG (chambered for the 7.5×55mm Swiss Schmidt–Rubin rifle cartridge), produced by the federal arms factory W+F.
Document 15: Wenger: Wenger is one of two companies that have manufactured Swiss Army knives. Based in Delémont, Wenger was acquired by rival Victorinox in 2005. Since 2013, Wenger Swiss Army knives are integrated in the Victorinox collection (as the "Delémont collection"); the brand Wenger remains for watches and licensed products.
ground_truth: The SG 540