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M16 5.56 BOLT CARRIER GROUP NICKEL BORON MP Reviews & Ratings

The Brownells M16 5.56 Complete Bolt Carrier Group is an affordable option that is built and tested to provide flawless operation in any AR-15 or M16. The Brownells M16 5.56 Complete Bolt Carrier Group features a bolt fabricated from 9310 steel that includes a heat-treated and shot-peened finish. The bolt carrier itself is built using 8620 steel, which features a hardened finish. The whole BCG is completed with a nickel-boron coating.

Steel quality assured with magnetic particle inspection
Features extractor with rubber insert and spring
Gas-key screws are torqued and staked
Designed for use with all 5.56-NATO-based cartridge cases.

The Brownells M16 5.56 Complete Bolt Carrier Group features a full assembly that includes the bolt, bolt carrier, gas key, firing pin, cam pin and a firing pin retaining pin.

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4 Stars

Reviews Summary

The M16 5.56 Bolt Carrier Group in Nickel Boron receives mixed reviews. Many users appreciate its affordability and reliable performance in their builds, while others criticize the NiB coating for not holding up well, showing carbon buildup and staining. While some report smooth operation, concerns about durability and material quality are prevalent.

What Reviewers Are Saying

Product Quality

45%

A significant number of reviewers praise the overall functionality and quality of the BCG, emphasizing its reliability during operation and installation ease. A few users note a good finish, reiterating their positive experiences with Brownell's in the past.

NiB Coating Issues

55%

Many reviewers express disappointment with the Nickel Boron coating, citing issues like poor cleaning, burns, and overall inadequate performance compared to higher-end alternatives. These negative experiences are a recurring theme, indicating a significant concern among users.

Affordability

50%

Several reviews mention the affordability of this BCG, particularly when purchased on sale. Users often find it to be good value for money, especially for budget builds. However, the low price comes with mixed feelings regarding quality and durability.

Installation and Compatibility

40%

Reviewers frequently highlight ease of installation and compatibility with various rifle builds. Positive remarks reflect that the BCG drops in easily and functions well with different setups, although there are some exceptions noted regarding sharp edges.

Durability Concerns

35%

A subset of reviewers reports durability issues, such as wear after minimal use and functioning problems with the bolt. The concerns raise questions about long-term performance, especially highlighted by multiple users who experienced functional failures after a limited number of rounds.

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Half good/half bad

For the price, it functions just fine for me, I got it on sale for ~$80, but as others have stated, there is a sharp and jagged edge on the carrier rail, it hasn't caused any issues so far, no bad wear marks inside the receiver. I will probably use some fine Emory cloth and polish up that edge. I pulled it apart to do some routine cleaning and found like another reviewer said, the same hard, black carbon buildup and thin coating on the backside of the bolt where it interfaces with the carrier inside. I had to use a hard scraper to remove the carbon buildup, but due to the thin/uneven coating I was unable to remove it all. The coating is bubbled/peeling on the backside of the bolt. Carrier seems ok, but the bolt is marginal due to the compromised surface. I will remove it and replace with a Sharps Relia-Bolt. Buyer beware.

needs better finishing

good deal nickel finish is good but needed tooling cleaned up before it was plated its really rough but nothing other then looks and cleaning would be an issue