Which BCG coating lasts the longest?

Nickel Boron and Nitride coatings are the most durable. NiB is smoother and easier to clean, while Nitride offers great corrosion resistance at lower cost.

Bolt Carrier Groups for AR-15, AR-10, and 9mm – Trusted BCGs from Top Brands

Q: What’s the best bolt carrier group for an AR-15?

A Nickel Boron full-auto BCG from brands like Fail Zero or WMD offers the best performance—it's smooth, durable, and easy to clean.

Q: Is there a difference between AR-15 and AR-10 BCGs?

Yes. AR-10 BCGs are larger and built for .308 or 6.5 Creedmoor, while AR-15 BCGs are for 5.56/.223. They are not interchangeable.

Q: Are full auto BCGs legal?

Yes. Full auto profile BCGs (M16-style) are legal for civilian rifles and do not make the firearm automatic.

Q: Do I need to lubricate a Nickel Boron BCG?

Yes, but less frequently. Nickel Boron coatings are self-lubricating and easier to maintain than phosphate or nitride BCGs.

Bolt Carrier Groups for AR-15, AR-10, and 9mm – Trusted BCGs from Top Brands

458 socom bcg

5.56/.223 BCG

6.5 Grendel BCG

6mm ARC BCG

7.62x39 BCG

9mm BCG

Bolt Parts

M16 BCG

AR Bolt Assembly

NiB BCG

**Ergo AR-15 Bolt Carrier Group (AR BCG)** $165.90

**Phase5 Bolt Carrier Group Ar15 Blk** $150.00

**Phase5 Bolt Carrier Group M16 Blk** $150.00

**KAK K-SPEC AR-15 BCG – Enhanced Carrier, Down Vent, Sand Cuts, Chrome Lined Phosphate** $103.49

**Fail Zero M16/M4 Full-Auto BCG – EXO Nickel Boron** $170.90

**Fail Zero Lightweight BCG – EXO Nickel Boron | 9.2 oz** $221.73

**Fail Zero M16 / AR-15 EXO Coated Bolt Carrier Group – Nickel Boron** $142.22

**Fail Zero EXO Coated AR-15 Bolt Carrier Group – Nickel Boron** $142.22

**Daniel Defense Bolt Carrier Group 5.56** $233.34

**CMC Triggers Enchanced Bolt Carrier Group Ar15 5.56/.223/300blackout** $199.00

**BCM® Bolt Carrier Group (MPI) – Auto – Flat Dark Earth | Mil-Spec | M16/AR15 Compatible** $244.04

**BATTLEARMS 9mm Ar15 Bolt Carrier Group Blk** $173.67

**Sons Of Liberty Gun Works Scalper Bolt Carrier Group** $199.51

**Sons Of Liberty Gun Works Bolt Carrier Group** $196.04

**Spike's M16 Bolt Carrier Group Blk** $139.84

**Spike's M16 Bolt Carrier Group Lw** $229.17

**Aero Ar9 9mm BCG Blk Nitride** $188.07

**Aero Ar15 5.56 Pro Series BCG Ntrd** $184.42

**Angstadt Arms Ar15 BCG 9mm Blk** $161.91

**Angstadt Arms Ar15 BCG 556nato Blk** $130.95

**BATTLEARMS M4/m16 Enhanced Bcg** $189.95

**BATTLEARMS 5.56 Ar15 BCG Titanium Armorti** $461.31

**BATTLEARMS M4/m16 Standard Bcg** $145.95

**Fail Zero 7.62×39 Bolt Carrier Group – EXO Nickel Boron** $170.90

Looking to upgrade or build a more reliable AR platform? Whether you're running a precision AR-15, a heavy-duty AR-10, or a 9mm PCC, we stock battle-tested bolt carrier groups (BCGs) from brands you trust.

At Mounts Plus, our curated collection of Nickel Boron, Nitride, and Phosphate BCGs covers every finish, caliber, and performance requirement. From Fail Zero’s EXO-coated carriers to Aero Precision, Spike’s Tactical, and others, we’ve got the right BCG for your build—ready to ship.

⚙️ What Is a BCG and Why It Matters

Your bolt carrier group is the engine of your AR. It controls chambering, firing, extraction, and cycling. If your BCG fails—your rifle fails. That’s why we only offer mil-spec or better BCGs, most of which are MPI-tested, properly staked, and ready for high-round-count abuse.

🔧 Types of Bolt Carrier Groups We Offer

✅ AR-15 BCGs (5.56/.223/300 BLK)

Full auto profile (M16)
Nickel Boron, Nitride, and Phosphate options
Drop-in ready and MPI-tested

✅ AR-10/.308 BCGs

For DPMS pattern rifles
9310 steel bolts and 8620 carriers
Available in polished NiB and black Nitride

✅ 9mm PCC BCGs

Glock and Colt-compatible options
Ideal for blowback builds
Hardened for heavy use

🛠️ Popular Finishes & Coatings

Nickel Boron BCGs: Smooth, self-lubricating, easy to clean
Black Nitride BCGs: Tough, corrosion-resistant, cost-effective
Chrome & Phosphate BCGs: Traditional and trusted

Not sure what to choose? Check out our guide: “Nickel Boron vs Nitride: Which BCG Coating is Best?”

🧱 Trusted Brands We Carry

Fail Zero – EXO-coated carriers, ultra-slick and durable
WMD Guns – NiB-X finish, polished and proven
Spike’s Tactical – Full auto BCGs with tight tolerances
Sons of Liberty Gun Works – Built for duty rifles
Aero Precision – Value and reliability

💥 Ideal For:

New rifle builds and upper kits
Replacing worn or out-of-spec carriers
Suppressed rifles or SBRs
High-round-count shooters
Precision and competition builds

🧠 FAQ:

What’s the best bolt carrier group for an AR-15?

A Nickel Boron full-auto BCG from a brand like Fail Zero or WMD is ideal. It’s durable, smooth, and easier to clean than phosphate or nitride.

Is there a difference between AR-15 and AR-10 BCGs?

Yes. AR-10 BCGs are larger and built for .308/6.5 Creedmoor rounds, while AR-15 BCGs are designed for 5.56/.223 and similar cartridges. They are not interchangeable.

Are full auto BCGs legal?

Yes. A full auto profile BCG (often called M16-style) is legal for civilian use and does not make your rifle automatic. It simply adds mass and durability.

Do I need to lubricate a Nickel Boron BCG?

Yes—but much less than phosphate or nitride. NiB BCGs are known for low friction and easy cleanup.

Which coating lasts the longest?

All coatings are durable, but Nickel Boron and Nitride are top-tier for longevity and corrosion resistance. Choose NiB for smoothness or Nitride for value.

🚀 Build with Confidence

We only stock tested, field-ready bolt carrier groups that meet the demands of shooters who expect performance and reliability. Whether you're upgrading or starting from scratch, the right BCG is just a click away.

In stock. Ready to ship. Built to last.