The SG550 serves as Switzerland’s standard-issue service rifle, featuring a gas-operated system with a cold hammer-forged barrel. You’ll find it chambered in 5.56×45mm NATO with a long-stroke piston design and rotary bolt locking mechanism. The rifle achieves 11cm groupings at 300m using GP 90 ammunition and includes ambidextrous controls with a side-folding stock. While its $1,700 MSRP may seem steep, its combat reliability and sub-4 inch groups at range reveal its true value.
Key Takeaways
- Swiss-made gas-operated assault rifle chambered in 5.56×45mm NATO with long-stroke piston system and selective fire capability.
- Features a cold hammer-forged 20.8-inch barrel delivering 11cm groupings at 300m with standard ammunition.
- Equipped with ambidextrous controls, side-folding stock, and Picatinny rail for mounting optics and accessories.
- Primary service rifle of Swiss Armed Forces with over 600,000 units deployed and variants used by international military forces.
- Retails new between $943-$1,676, with proven reliability in field operations and minimal maintenance requirements.
Description
The SIG SG 550 operates as a gas-actuated, selective-fire assault rifle chambered in 5.56×45mm NATO. You’ll find a long-stroke piston system paired with a rotary bolt locking mechanism and hammer-fired action.
The SG 550 series rifles feature a 20.8-inch cold hammer-forged barrel, ambidextrous controls, and a side-folding skeletonized stock. The SG includes adjustable iron sights, achieving 11cm groupings at 300m with GP 90 ammunition.
Price Range
Most SG550 rifles retail between $999.99 and $1,595.87, with a manufacturer’s suggested retail price of $1,700.00. You’ll find used models around $1,129.99, while authorized retailers like Guns.com and MidwayUSA offer varying price points. The rifle series’ cost fluctuates based on condition and seller location.
| Retailer Type | Price Range |
|---|---|
| MSRP | $1,700.00 |
| New Retail | $942.99 – $1,676.47 |
| Used Market | $999.99 – $1,595.87 |
| Sale Price | $1,611.99 |
| Used Average | $1,129.99 |
Specifications
The SG550 family offers varying specifications across its models to suit different operational needs. You’ll find the base SG550 weighs 4.1 kg and features a 20.8-inch cold hammer-forged barrel, while the shorter SG551 and 552 variants reduce weight and overall length for enhanced maneuverability. The rifles are constructed from high-grade steel and polymer components, chambered in 5.56×45mm NATO, and accept 5, 20, or 30-round magazines.
| Model | Barrel Length | Sight Radius |
|---|---|---|
| SG550 | 528mm | 540mm |
| SG551 | 363mm | 466mm |
| SG552 | 226mm | 360mm |
| SG553 | 226mm | 339mm |
| SG553 LB | 347mm | 339mm |
Weight
SIG SG 550’s empty weight comes in at 4.100 kg (9.0 lbs), with weight increasing to 4.440 kg (9.8 lbs) when equipped with a 20-round magazine and 4.580 kg (10.1 lbs) with a 30-round magazine.
The rifle features polymer components and an aluminum lower receiver to optimize weight. Variants offer lighter options, with the SG 551 carbine at 3.4 kg (7.5 lbs) unloaded and the compact SG 552 Commando at 3.2 kg (7.1 lbs).
Barrel Length
Standard barrel length on base SG 550 rifles measures 20.8 inches (52.8 cm), optimized for military service and precision shooting at extended ranges.
You’ll find shorter barrels on the carbine variants: the SG 551 offers 14.3″ or 17.9″ long barrel options, while the compact SG 552 Commando features an 8.9″ barrel.
The SG 553’s sight radius benefits from its 13.3″ barrel, affecting overall length.
Material Made Out Of
Built for durability and performance, SG 550’s construction combines high-strength polymers with hardened steel components. You’ll find the stock, handguard, and pistol grip crafted from lightweight polymer materials, while the core operating system features hardened steel parts.
The rifle employs a long-stroke gas piston system with a rotary bolt locking mechanism, complemented by a hooded front sight and cold hammer-forged barrel.
Chambered In
Versatility defines the SG 550’s chambering options, primarily offered in 5.6mm Gw Pat 90 and 5.56x45mm NATO calibers across its main variants. You’ll find these chambering options consistent throughout the rifle series, including the SR sniper variant, SG 551, and SG 552 Commando models.
The newer SG 553 expands beyond traditional offerings, featuring additional chambering choices in 7.62x39mm and .300 AAC Blackout.
Capacity
Magazines for the SG 550 offer multiple capacity options, with the primary configuration being a 20-round polymer magazine loaded with 5.56x45mm NATO ammunition. You’ll find additional magazine capacity choices including 30, 10, and 5-round variants.
All polymer magazines feature an interconnecting design for faster reloads. This magazine compatibility extends across the entire family, including the SG 551, 552, and 553 carbine variants.
Trigger Pull
The SG 550’s trigger system features a notably heavy pull weight of 35 Newtons (3.5 kg), setting it apart from many contemporary assault rifles. This deliberate design choice enhances reliability during intense operations, preventing accidental discharges when the gas system and recoil spring are under stress.
You’ll find the trigger pull remains consistent throughout the weapon’s service life, prioritizing safety over a lighter trigger feel.
Safety?
Safety features on the SG 550 include an ambidextrous fire selector switch that integrates seamlessly with its high-resistance trigger mechanism. The rifle’s safety system works in conjunction with its gas-actuated piston-driven operation, ensuring reliable function while maintaining control.
You’ll find the ambidextrous safety controls easily accessible from either side, complementing the charging handle and gas tube arrangement for enhanced operational security.
Action
Operating with a gas-actuated long-stroke piston system, the SG 550’s action delivers consistent cycling through its rotary bolt locking mechanism. The gas-operated design ensures reliable function while the spring-loaded extractor and fixed ejector work in tandem to effectively clear spent casings.
You’ll find this action type offers dependable performance across varied conditions, making it a hallmark of the rifle’s engineering excellence.
Optic Ready?
Building upon its reliable action system, SG 550’s optics configuration offers extensive customization options. You’ll find adjustable iron sights with a 540mm sight radius and precise 0.15 mil increments.
The rail on the upper receiver accepts various quick-detachable mounts, including the Kern 4×24 telescopic sight with tritium illumination.
Both SG 551 and 552 variants maintain compatibility while featuring shorter sight radii of 466mm and 360mm respectively.
Picatinny Rail?
The Picatinny rail system integrated into the SG 550’s upper receiver provides a standardized mounting platform with precisely machined slots at 0.394-inch intervals. You’ll find this SIG feature enables seamless attachment of various optics and accessories.
The modular Picatinny rail design accommodates red dot sights, magnified scopes, and optoelectronic devices, allowing you to customize your rifle’s setup for different operational requirements and environments.
Review
The SG550’s outstanding reliability and precision come from its robust gas system and cold hammer-forged barrel, though you’ll find its 8.9-pound weight and 40.9-inch length somewhat cumbersome for close-quarters operations.
You’ll appreciate the rifle’s ambidextrous controls, tool-free disassembly, and compatibility with various optics and accessories, making it a versatile platform primarily used by Swiss military forces and law enforcement agencies worldwide.
The rifle’s durability and accuracy have earned it a reputation as a premium service weapon, despite its relatively high cost and limited civilian availability in many markets.
Pros
Several standout features make the SG 550 a highly regarded combat rifle. You’ll appreciate its robust gas-operated system that ensures reliability in harsh conditions, while the 540mm long sight radius delivers exceptional accuracy. The folding stock enhances mobility in tight spaces.
| Feature | Benefit | Application |
|---|---|---|
| Gas Piston | Reliable Operation | All Weather |
| Modular Design | Easy Customization | Mission-Specific |
| Polymer Construction | Weight Reduction | Enhanced Mobility |
Cons
Despite its impressive engineering, significant drawbacks exist with the SG550 platform that you’ll need to consider. As a successor to the Stgw 57 battle rifle, this weapon presents reliability issues with its long-stroke gas system and complex maintenance requirements.
| Limitation | Impact | Consideration |
|---|---|---|
| Weight | 4.1 kg (9.0 lbs) | Heavier than competitors |
| Maintenance | Complex procedures | Increased service time |
| Magazine | Proprietary design | Limited compatibility |
| Cost | $1,700 MSRP | Higher price point |
| Operation | Selective-fire system | Less reliable performance |
Reliability
Real-world testing across diverse combat environments confirms the SG550’s exceptional reliability, contradicting earlier concerns about its gas system. The SG 550’s long-stroke gas piston ensures reliable cycling even when exposed to mud, dust, and extreme temperatures.
You’ll find it maintains consistent sub-4 inch groupings at 300 meters while requiring minimal maintenance. Military operators report negligible malfunctions during extended field operations and combat deployments.
Most Commonly Used By
The Swiss Armed Forces stand as the primary operator of the SG 550, having integrated over 600,000 units into their arsenal since 1990.
You’ll find the rifle in service with militaries and law enforcement across Greece, Pakistan, and Malaysia.
Special Operations units, including Switzerland’s Kommando Spezialeinheiten and Malaysia’s Pasukan Gerakan Khas, utilize the SG 551 and SG 552 variants, while Swiss Border Guard employs the SG 553.
Similar Models
Several variants of the SG550 were developed to meet diverse tactical requirements, starting with the SG 551 carbine featuring a shortened 14.3-inch barrel and lighter 7.5 lb weight.
The SG 552 Commando followed with an 8.9-inch barrel and 226mm sight radius.
You’ll find the SG 553 offers further improvements with its recoil spring system and multiple caliber options, including 5.56mm NATO, 7.62x39mm, and .300 Blackout.
Similar Models From Other Manufacturers
Comparable to the SG550’s design philosophy, numerous manufacturers developed their own modern assault rifles with similar features and capabilities.
You’ll find the FN FNC and Beretta ARX160 utilizing comparable long-stroke gas systems, while the H&K G36 mirrors the SG550’s folding stock design.
The Steyr AUG and Galil ACE demonstrate parallel evolutionary paths in NATO-compatible rifles, much like the SG 553 LB and Blackout variant.
Maintenance
Like many precision firearms, maintaining the SG 550 requires systematic attention to key components for optimal performance.
You’ll need to regularly disassemble and clean the gas piston and bolt carrier assembly. It’s crucial to inspect the barrel and chamber for fouling, removing any obstructions you find. Proper lubrication of all moving parts is essential to prevent wear and ensure reliable operation during extended firing sessions.
History
The Swiss-designed SG 550 emerged in the late 1970s as a much-needed replacement for the aging Stgw 57 battle rifle. Initially designated as the SG 541, it won selection over the W+F C42 in 1983 before being renamed SG 550 in 1984.
The rifle, featuring a long-stroke gas system, entered production in 1986 and was adopted as the Stgw 90 in 1990. Over 600,000 units were produced before military production ended.
Frequently Asked Questions
Is the SIG 550 a Good Rifle?
You’ll find the SIG 550 delivers exceptional reliable performance across all conditions. Its robust construction features a gas-operated system and cold hammer-forged barrel that ensures accurate long range shooting up to 400 meters.
The rifle’s modular design lets you adapt it to your needs, while its ergonomic features like ambidextrous controls enhance your shooting experience. With military-grade durability and proven service record, it’s a rifle you can trust.
Is the SIG 556 Discontinued?
If you’re looking to buy a new SIG 556, you’ll need to change your plans. The rifle was officially discontinued in 2020 when SIG Sauer ended its current production status.
While you can’t get one fresh from the factory anymore, you’ll still find them on the civilian market through secondary sales. SIG replaced it with the 716i model as they shifted their focus away from legacy designs to meet modern military procurement demands.
What Rifle Is Used by Navy SEALS?
You’ll find Navy SEALs primarily using the Sig Sauer MK18 CQBR as their standard-issue rifle, valued for its combat reliability in demanding conditions. This M4 carbine variant features a 10.3-inch barrel for enhanced maneuverability.
For specialized military use, they’ll also employ the Sig Sauer MCX series, offering superior long-range accuracy and modular customization. These weapons are specifically chosen to meet the rigorous requirements of SEAL operations in various combat environments.
What Caliber Is the SIG SG 550?
You’ll find the SIG SG 550 primarily chambered in 5.6x45mm Gw Pat 90, a round specifically engineered to deliver superior ballistic performance characteristics.
However, you can also get the SG 550-2 variant in 5.56x45mm NATO. While both calibers offer similar maintenance requirements and work with the rifle’s ergonomic features, the Gw Pat 90 round achieves higher muzzle velocity at 940 m/s from the standard 20.8-inch barrel length.
Conclusion
You’ll find the SG550 stands as solid as a Swiss mountain in the realm of battle rifles. Since its 1990 debut, this 5.56mm service weapon has proven its worth through exceptional accuracy and reliability. While you’re looking at $3000+ for civilian variants, the rifle’s rotary bolt system, adjustable gas regulator, and folding stock deliver military-grade performance. It’s remained largely unchanged, testament to its near-perfect engineering.
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