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Bolt Carrier Groups – AR-15, AR-10 & 9mm BCGs | Nickel Boron & Full Auto
Bolt Carrier Groups – AR-15, AR-10, & 9mm BCGs for Every Build
Precision Bolt Carrier Groups for AR Platforms of All Calibers
Looking for a reliable, battle-ready bolt carrier group (BCG) for your next AR build? Whether you're upgrading your AR-15, building out an AR-10, or dialing in a 9mm PCC, Mounts Plus has the right BCG to match your needs.
We carry mil-spec, Nickel Boron, Nitride, and Phosphate-finished BCGs from top-tier brands like Fail Zero, Aero Precision, BCM, Spike’s Tactical, and Sons of Liberty Gun Works — all trusted by competitive shooters, duty officers, and everyday gun owners alike.
🧰 What Is a BCG and Why Does It Matter?
The Bolt Carrier Group is the heart of your AR-15 or AR-10. It's responsible for:
- Cycling rounds and extracting spent casings
- Striking the firing pin with proper force
- Maintaining consistent chamber pressure
A poor-quality BCG means misfires, jams, and poor reliability.
🔧 Types of Bolt Carrier Groups We Offer
✅ Standard AR-15 BCGs (5.56/.223/300 BLK)
- Full-auto rated (M16 profile)
- MPI-tested bolts
- Compatible with all mil-spec AR-15 receivers
✅ AR-10 / .308 BCGs (DPMS / SR-25)
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.308 & 6.5 Creedmoor compatible
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Available in NiB and Nitride finishes
✅ 9mm BCGs (Glock & Colt Compatible)
- Designed for blowback operation
- LRBHO support (where applicable)
- Works with PCC lowers and 9mm AR uppers
✅ Lightweight & Competition BCGs
- TiN and DLC-coated options
- Reduced mass for faster cycling and competition shooting
🛡️ BCG Finish Options: What’s the Difference?
| Finish | Lubrication | Cleanability | Wear Resistance | Ideal For |
|---|---|---|---|---|
| Nickel Boron (EXO) | Self-lubricating | Easiest | Excellent | Suppressed, dirty ammo |
| Black Nitride | Needs oil | Easy | Great | General use |
| Phosphate | Needs oil | Harder to clean | Good | Budget builds or mil-spec purists |
🔍 Top Brands We Trust
- Fail Zero – Premium EXO-coated Nickel Boron BCGs
- BCM – Mil-spec phosphate M16 carriers
- Sons of Liberty Gun Works (SOLGW) – Battle-tested BCGs
- Aero Precision – Nitride-finished AR-15 and AR-10 BCGs
- Spike’s Tactical – Phosphate and lightweight carrier options
- CMC Triggers – Enhanced AR-15 BCGs for smooth function
- Phase 5, Angstadt Arms, and more...
🧠 BCG Fitment & Compatibility
All BCGs sold by Mounts Plus are:
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🔧 Drop-in ready for standard AR upper receivers
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🧱 Compatible with carbine, mid-length, and rifle gas systems
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✅ Available in Type I and Type II bolt face variants
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💥 Suitable for standard, suppressed, or competition rifles
Need a BCG for 6.5 Grendel, 7.62x39, 6mm ARC, or 458 SOCOM? We carry those too.
🔥 Best-Selling Bolt Carrier Groups
- Fail Zero AR-15 BCG – Nickel Boron
- Spike’s Tactical M16 BCG – Black Phosphate
- Sons of Liberty BCG – Full Auto Rated, Nitride Finish
- Angstadt Arms 9mm BCG – Glock-Compatible
❓ Frequently Asked Questions About Bolt Carrier Groups
Q: Do I need a full-auto BCG for my AR-15?
Yes. Full-auto carriers (M16 profile) are legal and provide extra mass for smoother cycling and reliability.
Q: Is Nickel Boron better than Nitride?
Nickel Boron is self-lubricating and easier to clean, especially in suppressed or high-round-count rifles. Nitride is a great, cost-effective alternative.
Q: Can I use an AR-10 BCG in my AR-15?
No. AR-10 and AR-15 BCGs are not interchangeable due to size and platform differences.
Q: What is MPI testing?
Magnetic Particle Inspection (MPI) detects micro-cracks in the steel, ensuring long-term durability.
Q: Are your BCGs made in the USA?
Yes. We stock U.S.-manufactured BCGs from trusted American brands.
🛒 Shop Bolt Carrier Groups Now
Upgrade your rifle with a BCG you can trust. From precision AR-15s to hard-use duty rifles and competition PCCs, Mounts Plus has the perfect bolt carrier group for every platform.