SIG SG 550 Sniper
SIG Arms AG · Sniper Rifle · In Production · 1998
Also known as: SG 550 Sniper, Stgw 90 Sniper, Scharfschützengewehr 550, SG550-1 Sniper
Overview
The SIG SG 550 Sniper is a precision-enhanced variant of the Swiss military's standard SIG SG 550 assault rifle, configured as a designated marksman rifle. Developed by SIG Arms AG (now Swiss Arms), the Sniper variant features a heavier cold hammer-forged barrel with an extra-heavy contour for improved accuracy and heat dissipation, a refined two-stage trigger with reduced pull weight of 15 N (compared to the standard 35 N), and a fully adjustable folding stock with cheek piece. Chambered in 5.56x45mm NATO optimized for Swiss GP 90 ammunition, the rifle delivers exceptional accuracy for its caliber class with consistent sub-MOA groupings. The SG 550 Sniper retains the semi-automatic capability of its parent design, giving designated marksmen rapid follow-up shot capability at ranges where the 5.56mm round remains effective.
Specifications
| Weight (empty) | 5400 g (190.5 oz) |
| Weight (loaded) | 5900 g (208.1 oz) |
| Overall Length | 1130 mm (44.49") |
| Folded Length | 905 mm (35.63") |
| Barrel Length | 650 mm (25.59") |
| Action Type | Gas Operated Rotating Bolt |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Two Stage |
| Trigger Pull | 15 N (3.4 lbf) |
| Magazine Capacity | 20 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 940 m/s (3084 fps) |
| Muzzle Energy | 1767 J (1303 ft·lbf) |
| Effective Range | 600 m (656 yd) |
| Maximum Range | 3600 m (3937 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 254 mm (10.00") |
| Number of Grooves | 6 |
| Frame Material | Steel |
| Barrel Material | Cold Hammer Forged Steel |
| Stock Material | Polymer Folding |
| Finish | Matte Black |
Calibers
- 5.56x45mm NATO · primary · 5.56x45mm NATO — also known as .223 Remington, 5.56 NATO, SS109
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety, Firing Pin Safety
- Features: Heavy Barrel, Cold Hammer Forged Barrel, Folding Stock, Adjustable Cheek Piece, Adjustable Pistol Grip, Adjustable Bipod, Refined Trigger, Accessory Rail
Variants
- SIG SG 550 — Base Model
- SIG SG 551 — Carbine
- SIG SG 552 Commando — Compact
Base model
Service history
Operators
- Swiss Armed Forces · adopted 1998 · as Scharfschützengewehr 550
- Swiss Police Units · adopted 1998
Production
Production years: 1998-present
Production numbers not publicly disclosed. Primarily used by Swiss military and law enforcement.
Origin
Country of origin: Switzerland
Notes
The SG 550 Sniper uses the Swiss military's 254mm (1:10 inch) rifling twist rate, optimized for the Swiss GP 90 (Gewehr Patrone 90) 5.56mm cartridge with its 4.1g FMJ projectile. The trigger pull is reduced from the standard 35 N to approximately 15 N for the sniper variant, significantly improving shot-to-shot consistency. The rifle can use standard 20-round SG 550 magazines as well as the standard 30-round version. The folding stock reduces overall length from 1,130mm to approximately 905mm for transport. The rifle's gas-operated rotating bolt action is derived from the AK/Kalashnikov family but refined to Swiss precision standards.
Background
The SG 550 Sniper embodies the Swiss philosophy of wringing maximum precision from a standard infantry cartridge. While most nations have moved to 7.62mm or larger calibers for designated marksman roles, Switzerland's mountainous terrain and shorter typical engagement distances make the lighter, lower-recoil 5.56mm an effective choice, allowing marksmen to carry more ammunition and maintain higher rates of accurate fire.