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SIG SG 550
The SIG 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 SG 550 is based on the earlier predecessor, the SIG SG 540, chambered in 5.56×45mm NATO.
In 1978, the Swiss armed forces formulated requirements for a successor to the Stgw 57 battle rifle (known commercially as 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 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 favour of the more conventional SIG 5.6×45mm Gw Pat 90 round (with a 4.1 g, tombac-jacketed, lead core projectile) that 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 the military has now ceased.
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 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 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.[citation needed]
The National Firearms Association of Canada considered pursuit of 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.
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 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 the second setting for use in the presence of heavy fouling or icing.
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SIG SG 550 AI simulator
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SIG SG 550
The SIG 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 SG 550 is based on the earlier predecessor, the SIG SG 540, chambered in 5.56×45mm NATO.
In 1978, the Swiss armed forces formulated requirements for a successor to the Stgw 57 battle rifle (known commercially as 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 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 favour of the more conventional SIG 5.6×45mm Gw Pat 90 round (with a 4.1 g, tombac-jacketed, lead core projectile) that 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 the military has now ceased.
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 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 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.[citation needed]
The National Firearms Association of Canada considered pursuit of 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.
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 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 the second setting for use in the presence of heavy fouling or icing.