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Quick Look

The SIG 551 is a Swiss-designed assault rifle developed in the late 1980s as part of the SIG SG 550 series. It offers a robust gas-operated system with a focus on accuracy and durability. Today, the SIG 551 remains a respected choice in military and tactical circles worldwide.

Why It's a Top Choice

High reliability in harsh conditions
Accurate 5.56x45mm NATO chambering
Versatile folding stock design
Robust Swiss manufacturing quality
Good aftermarket optics compatibility

Key Variants

SIG 551 Carbine

Compact variant suited for close quarters and special operations units.

SIG 551 SWAT

Enhanced version with accessories for law enforcement tactical teams.

SIG 552 Commando

Short-barrel model favored for its maneuverability in urban settings.

Competitor Comparison Table

Feature	SIG 551	HK416	FN SCAR
MSRP	$2,500+ (varies by config)	$3,000+	$3,500+
Capacity / Size	20-30 rounds, 20\" barrel	30 rounds, 14.5-16\" barrel	20-30 rounds, 16.25\" barrel
Weight	8.4 lbs (3.8 kg)	7.9 lbs (3.6 kg)	7.9-8.9 lbs
Optics-Ready	Yes, integrated rail	Yes, Picatinny rail	Yes, modular rails
Trigger Type	Double-action/single-action	Single-stage	Single-stage
Notable Pro	Exceptional build quality	Proven in military use	Highly modular platform
Notable Con	Heavier than peers	Higher price point	Limited aftermarket

Best Use Cases

Military and tactical applications
Law enforcement duty use
Range training and marksmanship
Home defense for experienced users
Firearms collection and enthusiasts

FAQs

Can I use standard 5.56 NATO magazines with the SIG 551?

Yes, the SIG 551 accepts standard STANAG 5.56x45mm NATO magazines compatible with NATO rifles.

What type of gas system does the SIG 551 use?

It utilizes a short-stroke gas piston system for reliable cycling and reduced fouling.

How does the SIG 551 perform in adverse conditions?

The rifle is renowned for durability and reliability in harsh environments, maintaining function in cold and dusty conditions.

SIG 551 for Sale