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5.56/.223 BCG – AR-15 Bolt Carrier Groups | Nickel Boron & Full Auto
5.56/.223 BCG – Bolt Carrier Groups for AR-15 Rifles
Precision-Crafted BCGs for Your 5.56 or .223 AR-15 Build
Your bolt carrier group (BCG) is the heart of your AR-15 rifle. Whether you’re building from scratch or upgrading your current setup, choosing a reliable 5.56/.223 BCG ensures smooth cycling, consistent ignition, and long-term durability.
At Mounts Plus, we offer premium 5.56/.223 bolt carrier groups from leading brands like Fail Zero, WMD Guns, Sons of Liberty Gun Works, Aero Precision, and CMC Triggers — all designed for serious shooters, competitive marksmen, and home defense professionals.
🔧 Why a Dedicated 5.56 BCG Matters
Although .223 and 5.56 NATO share similar specs, your bolt carrier group needs to be mil-spec rated to handle 5.56 pressures. A proper 5.56 BCG ensures:
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✅ Full-auto rated mass for smoother cycling
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✅ Reliable ignition with hard primers
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✅ Nickel Boron, Nitride, or Phosphate coatings for long life
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✅ Compatibility with .223, 5.56 NATO, and .223 Wylde barrels
A poor-quality BCG can lead to misfires, extraction failures, and early wear — don’t compromise your rifle’s reliability.
🧰 Top 5.56/.223 BCG Options Available
Fail Zero 5.56 BCG – Nickel Boron (No Hammer)
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EXO-coated for self-lubrication
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MPI-tested bolt, full-auto profile
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Easy to clean and highly corrosion-resistant
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Drop-in compatible with all AR-15 platforms
WMD Guns NiB-X BCG – With or Without Hammer
- Polished NiB-X finish
- Designed for suppressed or high-volume shooting
- Includes properly staked gas key, firing pin, cam pin, retaining pin
Sons of Liberty Gun Works BCG – Phosphate or Nitride
- Battle-tested full auto carrier
- Shot-peened, high-pressure tested bolt
- Built for military-grade durability
⚙️ BCG Coating Comparison: NiB vs Nitride vs Phosphate
| Feature | Nickel Boron (NiB) | Black Nitride | Phosphate |
|---|---|---|---|
| Self-Lubricating | ✅ Yes | ❌ No | ❌ No |
| Cleanability | ✅ Easy | ✅ Moderate | ❌ Harder |
| Corrosion Resistance | ✅ Excellent | ✅ Very Good | ⚠️ Moderate |
| Ideal For | Suppressed, high-volume | General use | Budget builds |
Nickel Boron BCGs are the gold standard for premium performance. Choose Nitride for all-purpose builds and Phosphate for mil-spec authenticity.
🎯 Perfect for All Use Cases
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🔫 Tactical/duty rifles
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🏹 Hunting builds
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🎯 Competition setups
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🧰 Range/training ARs
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🔇 Suppressed platforms
All BCGs listed are drop-in ready for mil-spec AR-15 uppers chambered in 5.56 NATO, .223 Remington, or .223 Wylde.
🔍 Why Choose Mounts Plus?
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✅ Trusted brands like Fail Zero, WMD, SOLGW, and Aero
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🚚 Fast shipping from U.S. inventory
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💬 Expert support for AR-15 builders
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🔐 Secure checkout and satisfaction guarantee
🔄 Related Components
❓ FAQs – 5.56/.223 Bolt Carrier Groups
Q: Is a full-auto BCG legal in a semi-auto AR-15?
Yes. M16-profile BCGs are legal and standard in today’s AR builds. They do not make your rifle full-auto.
Q: Can I use this BCG with .223 Wylde barrels?
Yes. These BCGs are compatible with .223 Wylde, .223 Rem, and 5.56 NATO chambered barrels.
Q: Is Nickel Boron worth the extra cost?
For high-round-count or suppressed rifles, absolutely. It runs cleaner, requires less lube, and wipes clean easily.
Q: Are these BCGs mil-spec?
Yes. All models sold here meet or exceed mil-spec, and many include extra testing like MPI and HP.
🛒 Shop 5.56/.223 BCGs Now
Upgrade your AR-15 with a bolt carrier group engineered for performance and durability. Whether you shoot recreationally, professionally, or defensively — we've got the BCG to meet your needs.