7 Best BCGs (Bolt Carrier Group) For AR-15s

The heart of any AR-15 is its bolt carrier group, playing a critical role in the function and performance of the firearm. With so many options on the market, finding the perfect BCG for your AR-15 can definitely be a challenge. Therefore, we decided to create a guide based on personal experience on the seven best BCGs available. We evaluated them based on durability, reliability, and user-friendliness.

These picks represent our personal satisfaction with these products as well as represent a range of offerings suitable for everyone, from the casual shooter to the dedicated enthusiast. Below is a list of the best BCGs for an AR-15.

  1. Aero PrecisionEditor’s Choice
  2. Bravo Company MFGMost Durable BCG
  3. WMD 5.56 AR-15#1 Nickel Boron BCG
  4. Faxon Firearms Gen 2Best For Competitive Shooters
  5. Radian Weapons Enhanced Black NitrideMost Precise
  6. TRYBE Defense Mil-SpecBest American Made BCG
  7. Walker Defense Research TitaniumBest Lightweight BCG
#1 Most Durable BCG
#1 Nickel Boron BCG
Best BCG For Competitive Shooters

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#1 Nickel Boron BCG
Best BCG For Competitive Shooters
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1) Aero Precision AR15 Bolt Carrier Group

HuntersHalt: #1 Pick
Aero Precision AR15 5.56mm Bolt Carrier Group (BCG)

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  • Built To Last (8620 Tool Steel)
  • Easy Installation
  • Different Finishes Available
  • Cheaper BCGs Available
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Aero Precision is one of the most well-respected companies not only in the BCG world but also in the entire AR-15 sector. They are renowned for their high-quality products and their strong foothold in the firearms industry.

From my experience, this BCG is one of the most durable and reliable BCGs I’ve used. Its carrier key is machined from 8620 steel, and the bolt is made from 9310 steel – both offering extreme strength and longevity. One of the things I love most about it is the black nitride finish, giving it a sleek look and making it highly resistant to corrosion and wear.

This BCG, with its indexed and more robust cam pin design, is perfect for those who want reliability, especially in a duty rifle. Whether you’re an enthusiast, a law enforcement officer, or just a range regular, you’ll appreciate the engineering finesse and robustness Aero brings to the table.

However, the black nitride finish, while smooth and sleek, may not appeal to everyone’s aesthetic tastes. Its size and weight are pretty standard, which might be a con if you’re going for an extremely lightweight build. But if you are looking for the most reliable, best BCG on the market, then this is the one to get!

Aero Precision BCG

2) Bravo Company MFG Bolt Carrier Group

#1 Most Durable BCG
Bravo Company MFG Bcm Bolt Carrier Group

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  • Different Colors Available
  • Very Easy To Clean
  • Very High Quality BCG
  • Only 1 Finish Available
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This BCG screams “military standard” in every aspect. It’s made to USGI specifications with a manganese phosphate finish that offers excellent corrosion resistance. What stood out for me has to be the quality of the bolt assembly, constructed from mil-spec Carpenter No. 158 steel, and features a properly staked gas key.

This BCG is best suited for those who want a battle-ready, high-functioning AR-15, M16, or M4. If you’re in law enforcement, military service, or a civilian looking for a robust, reliable BCG – this is it.

While this BCG has many pros, it’s worth mentioning that the manganese phosphate finish tends to retain more dirt and carbon, making it harder to clean compared to its nickel boron and nitride-finish counterparts.

Bravo Company BCG

3) WMD 5.56 AR-15 Bolt Carrier Group

#1 Nickel Boron BCG
WMD Guns AR-15Full Auto Bolt Carrier Group

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  • Lasts Forever (NiB-X Nickel Boron Coating)
  • Compatible With Different AR Platforms
  • Works In Short Barrel & Suppressed Platforms
  • Cheaper Options Available
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WMD has a solid reputation, especially for their innovative nickel boron products, and it really shows in their AR-15 BCG. The WMD BCG shines when it comes to ease of cleaning and smooth operation, thanks to its proprietary NiB-X nickel boron coating. I found this to be a real benefit during long-range days or high-volume shooting sessions.

It’s also heat-treated, with the carrier made of 8620 steel and the bolt from Carpenter 158 steel – providing the perfect balance of strength and durability.

This BCG is perfect for shooters participating in competitions or regularly engaging in high-volume shooting. The ease of cleaning and super-smooth action makes it an ideal choice in these scenarios.

However, this BCG does not include the hammer, which could add to the total cost of the BCG for some. Its weight is fairly standard (12 ounces), which could also be a con for those seeking an ultra-lightweight bolt carrier group.

4) Faxon Firearms Gen 2 Bolt Carrier Group

Best BCG For Competitive Shooters
Faxon Firearms Gen 2 9mm PCC Bolt Carrier Group

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  • Great For Competitive Shooters
  • Highly Durable (8620 Steel)
  • Has Full-Auto Compatibility
  • Only 1 Color & Finish Available
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The Faxon 9mm BCG is specifically designed for pistol-caliber carbines. It’s compatible with both Glock and Colt-style lower receivers, which I found extremely useful. The full-mass carrier is heat treated, and it comes with a salt bath nitride finish – making it durable and easy to clean.

If you are a pistol caliber carbine enthusiast or a shooter who prefers 9mm AR builds, this BCG is designed for you. In fact, most AR-15 pistols are chambered in 9mm with this style BCG.

However, it is important to note that it is incompatible with all lower receivers, especially Spike’s Tactical Colt 9mm lowers, which we covered in our AR-15 lower receiver article. Also, I’m not a big fan of this BCG’s heft weight – at 14.9 ounces, it might not be the best choice for those who prioritize lightweight and maneuverability.

Nonetheless, Faxon Firearms is renowned for their engineering prowess and consistency with regard to producing high-quality components for the AR-15 platform, making this the best bolt carrier group for 9mm AR builds.

5) Radian Weapons Enhanced Black Nitride Bolt Carrier Group

Precision Designed
Radian Weapons Enhanced Black Nitride Bolt Carrier Group

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The Radian BCG impressed me with its design aimed at minimizing carrier tilt and friction. It features a shot peened bolt, meeting and exceeding Mil-Spec standards. Plus, the carrier’s 8620 steel construction and black nitride finish makes it very resistant to wear and corrosion while keeping it looking sleek.

This BCG would suit any AR-15 or M16 owner who values high performance, reliability, and durability and can afford to pay a little extra. I found that it is also especially suitable for those who use their firearms heavily, whether at the range or in the field.

The main con with this BCG is that it is a bit pricey compared to the other options. However, Radian’s brand reputation for quality and high performance can easily justify the investment.

6) TRYBE Defense Mil-Spec AR-15

Best American Made BCG
TRYBE Defense Mil-Spec 5.56 Enhanced Complete Bolt Carrier Group

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I love TRYBE products, mainly because they have found the ability to create high-quality products at a considerably lower price point than their competitors. This BCG is a prime example of that recipe. The TRYBE Defense BCG stands out for its range of finishes it offers.

This BCG is machined from ultra-durable and corrosion-resistant 8620 steel, hardened to mil-spec conditions, promising years of reliable service. Additionally, its weight of 11.3 ounces is fairly standard, which makes it a great intermediate option.

If you’re someone who shoots different calibers, wants a variety of finishes to choose from, or wants a budget-friendly option, then this BCG is for you. The performance and flexibility it offers make it suitable for any AR-15 owner.

7) Walker Defense Research Titanium Bolt Carrier Group

Best Lightweight BCG
Walker Defense Research Titanium Bolt Carrier Group

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Last on our list, we have the Walker Defense BCG, which impressed me right from when I opened the box.

Like many of its counterparts, this BCG also boasts a nickel boron coating, giving it a very high hardness, wear resistance, and lubricity. But what sets it apart is the fact that it is a titanium bcg, or well predominantly, the carrier is made from 6AL-4V titanium, and the bolt is made from 9310 steel. But the fact that the carrier is made from titanium enables this BCG to be roughly 67% of the weight of standard steel BCGs – it only weighs 7.8 ounces!

When you pair this BCG with an adjustable gas block, it works like a dream. If you are someone who prefers lightweight bolt carrier groups, then this is the BCG to get. Additionally, this BCG is perfect for use in competition shooting.

However, the Walker BCG is quite expensive compared to the other bolt carrier groups on this list. However, if you are a serious shooter looking for the most lightweight bolt carrier group on the market, then buying this BCG might make it a worthwhile investment.

What Is A Bolt Carrier Group?

A bolt carrier group (BCG) is integral to a firearm’s gas system, especially in semi-automatic and automatic rifles like the AR-15. It comprises the bolt, bolt carrier, bolt gas rings, gas key, cam pin, and firing pin.

Why Is The Bolt Carrier Group Important For And AR-15?

The BCG is crucial for an AR-15 as it’s mainly responsible for the critical steps in the firing process, such as loading, firing, extracting, and ejecting the cartridge. It cycles the rounds, facilitates firing when the trigger is pulled, and resets the trigger mechanism.

Which BCG Is Best For A Suppressed AR-15?

Choosing a BCG for a suppressed AR-15 depends on your personal preference with regard to weight, price, and construction material. But I normally opt for a nickel boron BCG for suppressed AR-15s due to their slick surface, which improves functionality and makes it cleaning easier – the Aero Precision and WMD are excellent BCGs for a suppressed AR-15.

What Are The Types Of AR-15 BCGs?

The primary types of AR-15 BCGs are Full Auto (M16) and your standard Semi-Auto bolt carrier groups. Full auto BCGs generally have more mass towards the rear, enhancing durability and reliability. It can operate in both semi-automatic and fully-automatic AR-15s. In comparison, a semi-automatic BCH has less material in the rear, reducing its weight, and is only designed to operate in semi-automatic mode.

What Are The Benefits Of A Full Auto BCG?

Full Auto BCGs are generally more robust and reliable due to their increased mass. They can sustain more rigorous use and heat, making them ideal for heavy shooting sessions, which is the case in combat. They are also compatible with both semi and full-auto AR15s & other firearms.

What Are The Benefits Of A Semi-Auto BCG?

Semi-auto BCGs are lighter due to their design, leading to less weight in your rifle. They’re ideal for casual shooters or those who value a lightweight setup. Semi-auto BCGs are also typically less expensive than their full-auto counterparts due to less material and machining required in their manufacture.

What Factors Make A Good Bolt Carrier Group?

When we rate a bolt carrier group, we typically look at the following factors to decide whether it is a good BCG:

  • Material: The type of material is vital in determining whether a BCG is good. We are looking for one that has either a high-quality steel or titanium construction.
  • Coating: Remember, the type of coating or finish affects the BCG’s ease of cleaning, corrosion resistance, and general performance. Common coatings include chrome lined, phosphate, nitride, and nickel boron. We like seeing either chrome lined, nitride, or nickel boron in a BCG.
  • Manufacturing Process: Whether the BCG is MPI (Magnetic Particle Inspected) and/or HPT (High-Pressure Tested), ensures that it’s free from any potential cracks or defects.
  • Proper Staking: The gas key should be properly staked to ensure reliability and prevent loosening over time.
  • Brand Reputation: Brand reputation is very important – a good BCG often comes from a reputable manufacturer known for their high-quality firearm components.

What Are The Different Types Of BCG Coatings?

Different BCG coatings can significantly impact the performance and longevity of your BCG. Below are the most common types of BCG coatings.

  • Parkerized (Phosphate): Phosphate coating is a chemical process that provides a modest level of protection against corrosion and wear. It’s often seen in military applications and offers a matte black appearance.
  • Diamond-Like Carbon (DLC): DLC coatings have properties similar to diamond in terms of hardness, and they offer excellent wear resistance. They’re also known for reducing friction, resisting corrosion, and are typically easier to clean.
  • Nickel Boron: Nickel Boron coatings are hard and offer superior corrosion resistance. They are also wear-resistant and have a low friction coefficient, which results in a smoother action.
  • Electroless Nickel PTFE (NP3): NP3 is an electroless nickel-based finish for steel and metal alloys that co-deposits sub-micron particles of PTFE (polytetrafluoroethylene), commonly known as Teflon. It offers low friction, excellent wear, and corrosion resistance, and reduces the need for regular cleaning and maintenance.
  • Black Nitride: Black Nitride, or Ferritic Nitrocarburizing, is a heat treatment process that improves wear resistance, reduces friction, provides some corrosion protection, and makes the BCG easier to clean due to its slick surface.
  • Hard Chrome: A chrome-lined carrier involves electroplating a thin layer of chromium onto the BCG. It increases the hardness of the surface, reducing wear and decreasing the coefficient of friction, but it is less common in modern BCGs.
  • Titanium Nitride (TiN): TiN is a hard ceramic material often used as a coating for its gold-like appearance. It offers increased hardness, and heat resistance and reduces friction, which can enhance the overall performance and extend the life of the BCG.

Are There Other AR-15 Upgrades?

There are many AR-15 upgrades you can get for your AR-15. If you want to improve the precision of your AR-15, you might consider upgrading your optic to a red dot sight or scope, as well as upgrading your barrel.

Alternatively, if you want your AR-15 to be more adept for fast-paced situations, you might swap out your upper receiver for a lighter model or get a trigger that is ideal for these scenarios. The options are really endless – you even get upgrades to make your AR-15 more aesthetic.

Should You Mount A Red Dot Sight On An AR-15?

Red dots, like EOTech’s exps and xps, offer numerous benefits over traditional iron sights. I make it a priority to mount a red dot sight whenever I acquire a new AR-15. They are perfect for short-to-mid-range shooting and hunting encounters.

When you use a red dot sight, you will notice your target acquisition speed increase considerably, as well as your accuracy. A red dot sight is also a more effective aiming platform in low-light conditions. Ultimately, it comes down to personal preference, but if you can spare a couple of hundred dollars, then I would advise you to definitely think of getting a red dot sight for your AR-15.

Should You Mount A Scope On Your AR-15?

In addition to the standard red dot optic, you also get scopes that offer better magnification and more brightness settings, making them perfect for AR-15 rifles, like the MP 15 Sport 2 from Smith and Wesson.

These scopes are more versatile than your standard red dot sight and enable you to shoot targets at further distances as well as in more variable ambient light conditions. However, they also make your rifle more cumbersome.

So, deciding whether to mount a scope or optic ultimately comes down to your use case – for instance, I prefer a scope for medium-range hunting and range shooting, but for self-defense and turkey hunting, I prefer a red dot sight.

Can You Keep Your Used BCG With A New Upper Receiver?

Yes, you can keep your BCG when acquiring a new AR upper receiver. However, just make sure that the BCG is compatible with the new upper receiver and that it is in good working condition.

Frequently Asked Questions

How often do you need to clean your AR-15 BCG?

It depends on your shooting environment, shooting frequency, the amount of shooting, and the type of BCG coating you have. But I prefer to clean my BCG every 250-500 rounds.

Is it legal to upgrade your AR-15 Bolt Carrier Group?

Yes, it is legal to upgrade your BCG in most jurisdictions.

How does a bad BCG affect your AR-15's accuracy?

A faulty, worn-out, or even dirty BCG can often cause cycling issues, feeding problems, and inconsistent lockup, affecting your AR-15's accuracy and overall performance.

The Bottom Line

In conclusion, whether you’re an avid marksman, tactical trainer, or simply just a firearm enthusiast, choosing the right BCG can significantly enhance your AR-15 performance. We hope you found value in this guide and that you identified the perfect BCG for your use case. Always remember that a reliable BCG is fundamental to the reliable operation of your AR-15. The perfect BCG for you ultimately depends on your unique needs, preferences, and budget.

About the author

Patrick Howard

I have been working as a gunsmith for 20 years. Rain, fog, moisture, high temperature, or even snow are all the things a product must withstand in order to be recommended by me.

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