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Sig Rifle Accessories – MCX, MPX, 556 Parts & Upgrades | MSP

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Sig Rifle Accessories – Upgrade Your Sig MCX, MPX, and 556

Premium Accessories for All Sig Sauer Rifle Platforms

Enhance your Sig Sauer rifle with precision-engineered accessories built for performance and reliability. Whether you run a Sig MCX, MPX, 556, or SPEAR LT, Mounts Plus offers factory OEM and battle-tested aftermarket accessories to build, upgrade, or maintain your rifle platform.


🔧 Top Sig Rifle Platforms We Support

  • Sig MCX – Modular battle rifle with upgradeable barrels, stocks & gas systems

  • Sig MPX – 9mm PCC built for speed and suppression

  • Sig 556 – Classic Swiss-style semi-auto with folding stock options

  • Sig SPEAR LT – New-gen tactical rifle with ambidextrous controls


🔎 Shop by Accessory Category

Accessory Type Compatible Rifles Use Cases
Triggers MCX, MPX Precision, competition
Stocks & Braces MCX, MPX, 556 Folding, telescoping, PDW
Handguards MCX, SPEAR LT Suppressor-ready, M-LOK
Barrels & Kits MCX Caliber conversion
Uppers & Carriers MPX, MCX Build kits, spares
Charging Handles & Controls All Ergonomics & ambi control
Mounts & Optics All Sight systems, red dots

🔥 Featured Sig Rifle Accessories

Product Rifle Description Price
MCX Flat Trigger (TriggerTech) MCX Drop-in precision trigger $279.99
MPX Ambi Charging Handle MPX Smooth bilateral control $93.08
Folding PCB Stock MCX / MPX Compact, durable brace $173.05
MCX Caliber Conversion Kit – 300 BLK MCX Barrel, bolt, gas kit $776.05
556 Sight Set – Front & Rear SIG 556 Steel, adjustable $190.64

🧩 Compatibility Tips for Sig Accessories

  • MCX Virtus & SPEAR LT require Gen2/Gen3 parts

  • MPX barrels and bolts are unique to the 9mm platform

  • 556 series uses specific trigger and stock geometry

  • Use caliber kits to convert your MCX to .300 BLK or 5.56 NATO

Need help choosing the right accessory? Contact our firearm experts →


📋 Why Upgrade Your Sig Rifle?

  • 🎯 Improve accuracy and trigger response

  • 🔁 Change caliber for training or defense

  • 🔧 Customize ergonomics to your mission profile

  • 💪 Replace worn or hard-to-find OEM components

  • 🔦 Add lights, optics, and rail accessories via M-LOK or Picatinny


❓ Sig Rifle Accessories – Frequently Asked Questions

Q: Are MCX and MPX accessories interchangeable?
No — each platform has its own dimensions and gas system. Always choose accessories designed for your specific Sig model.

Q: What’s the most popular upgrade for Sig rifles?
Drop-in triggers, folding stocks, and suppressor-ready handguards are among the most common upgrades.

Q: Can I convert my Sig MCX to a new caliber?
Yes. MCX Caliber Exchange Kits allow for conversion between 5.56 NATO, .300 BLK, and 7.62x39.


⭐ Why Mounts Plus?

  • ✅ Trusted supplier since 1993

  • ✅ Factory OEM and high-performance aftermarket gear

  • ✅ Fast U.S. shipping and easy returns

  • ✅ Firearm experts available for product advice


🚀 Ready to Customize Your Sig Rifle?

From complete MCX builds to simple trigger upgrades, Mounts Plus carries the Sig rifle accessories trusted by professionals, competitors, and responsible citizens alike.