BCM® Bolt Carrier Group (MPI) – Auto | Mil-Spec | M16/M4/AR15 Compatible
Not Yet Rated | Write the First Review SKU: 222-BRA-BCM-BCG-AUTO
UPC: 813000000000
MFG#: BCM-BCG-AUTO

Stripped carrier is finishedA

 

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BCM® Bolt Carrier Group (MPI) – Auto | Mil-Spec | M16/M4/AR15 Compatible

Mil-Spec Built. Combat Proven. BCM® Reliable.

The BCM® Bolt Carrier Group (MPI) – Auto is trusted by professionals, competitors, and duty-driven shooters for a reason—it’s precision-machined to meet true U.S. Mil-Spec standards, test-fired for function, and built with battle-grade materials for maximum reliability in M16, M4, or AR-15 platforms.

From the Carpenter No. 158® steel bolt to the chrome-lined carrier and gas key, this BCG is designed to withstand hard use, maintain a perfect gas seal, and keep your rifle cycling smoothly in any environment.

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⚙️ Key Features:

• ✅ Full-Auto (M16) Bolt Carrier Group – Compatible with AR-15, M16, and M4

• ✅ Magnetic Particle Inspected (MPI) & High Pressure Tested (HPT) – Bolt strength and flaw detection verified

• ✅ Mil-Spec Carpenter No. 158® Steel Bolt – Shot peened for increased surface strength

• ✅ Tool Steel Extractor & Ejector – Built for consistent extraction under pressure

• ✅ Properly Staked Gas Key – Secured with Grade 8 fasteners per USGI specs

• ✅ Chrome Lined Gas Key & Carrier Interior – Corrosion resistance and smooth function

• ✅ Parkerized Exterior Finish – Rugged and field-proven

• ✅ Function Test Fired at Factory – Each BCG is verified before shipping

• ✅ Includes BCM® Extractor Spring Upgrade – Improves reliability with all ammo types

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🔫 Built for Battle, Trusted for Life

The BCM® Auto BCG is more than just a bolt carrier—it’s the beating heart of a serious-duty AR. Whether you're building a home defense rifle, outfitting a duty carbine, or upgrading your competition rig, this BCG offers zero compromise in quality or performance.

With MPI, HPT, shot peening, and BCM's elite attention to Mil-Spec detail, this is the bolt carrier group your rifle deserves.

in an Ion Bonded Black. Lowers friction and cleans easier.

BCM (MPI) complete bolt carrier group is fully assembled. (BCG)
Bolt carrier group (auto version) for your AR15, M16, or M4. Parkerized exterior and chrome lined inside carrier. Machined to USGI specifications. This M16/M4 carrier includes the proper Mil-Spec gas key. Gas key is chrome lined and heat treated per GI specifications. Gas key is secured to carrier via USGI domestic mfg Grade 8 fasteners and properly staked per Mil-Specs. These properly hardened parts ensure a strong staking and proper gas system functioning.

The bolt assembly is machined from the correct Mil-Spec Carpenter No. 158 steel, shot peened for increased strength, includes tool steel machined extractor and ejector, BCM Extractor Spring, and is HPT (High Pressure Tested) and MPI (Magnetic Particle Inspected).