There are a few parts of an AR that are as important as the bolt carrier group.
While the standard Mil-Spec bolt carrier does its job well and has for decades, new improvements in technology and materials have come along and revolutionized the design.
When looking at the Best Bolt Carrier Group to use for any AR-15, there are several factors one must consider.
Like many aftermarket pieces for ARs, much depends on what the intended purpose of the weapon is, what sort of budget you have to work with, firing frequency, and of course aesthetic appeal.
However, before we delve into the finer points, let's first understand what a bolt carrier group is and what sorts of duties it performs.
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What is a Bolt Carrier Group?
The bolt carrier group or shortly BCG is the component responsible for loading, firing, and extracting the ammunition. It’s made of several parts working together ensuring these actions are correctly performed.
BCG consists of a bolt, a bolt carrier, and a gas key at the most basic level.
Each part of the BCG has its purpose in the firing process:
- The bolt locks into the barrel and fires the round.
- The bolt carriers move back and forth extracting the spent shell and inserting another round into the barrel.
- The gas key allows gas from the barrel to enter the BCG driving the bolt carrier group back after shooting.
The BCG is the backbone of your AR-15 rifle as it is crucial to the rifle's reliability, functionality, accuracy, and performance.
A top-notch BCG is made of durable materials such as steel or titanium and has a durable finish that can stand up to wear and corrosion.
It should be easy to disassemble and clean, and its gas key should be properly staked to prevent it from coming loose during use.
A well-made BCG ensures proper alignment with the barrel, which can make all the difference in hitting your target.
It can also help take the edge off the recoil, making it easier to handle and allowing you to get back on target for a quick follow-up shot.
So when it comes to choosing a BCG, it’s best to stick with a reputable manufacturer with a solid track record and you won't go wrong.
Three types of BCGs
For the most part, bolt carrier groups come in three different options:
- M-16
- AR-15
- Lightweight.
Both the M-16 and AR-15 share many of the same characteristics, but each has its purpose and function. The M-16 version is heavier and has a long, full-size rear section.
The increased mass remains in the battery longer and is designed to withstand the abuse of fully automatic fire as well as match-grade guns.
The AR-15 BCG on the other hand is designed for semi-automatic fire and cycles faster, usually because of its lighter weight.
Lastly, the lightweight/Low Mass BCG is built for ultra-light competition guns that require several other parts for it to function reliably. Precision tuning is also needed for it to run at its best.
Why upgrade to a better bolt carrier group?
Are you ready to take your rifle to the next level? Let's talk about bolt carriers and why upgrading them can make all the difference.
Sure, you may already know about the three types of bolt carriers, but have you considered how your shooting habits and rifle demands play a crucial role in determining the best BCG for you?
Don't settle for a mediocre performance - upgrading your bolt carrier can elevate your shooting experience to a whole new level. Let's explore the possibilities together.
Maximize your rifle's potential with these four compelling reasons to upgrade.
- Improved Reliability
By upgrading to a heavier steel bolt carrier group, you can experience improved gun cycle time and minimized stress on spent brass, making it a desirable option for avid reloaders.
Additionally, the weight of the BCG can aid in the rifle's ability to accommodate a wider range of ammunition with minimal adjustments required.
Notably, the durability and reliability of steel BCGs have made them the preferred choice for military and law enforcement, given their capability to withstand rigorous use and high-volume firing.
- Improved Durability
Titanium is not only lighter but also stronger than steel, making it ideal for handling hotter loads and extreme pressure with ease.
However, the benefits come at a cost, as titanium is typically more expensive than steel.
On the other hand, a coated or plated BCG offers a slick surface that is incredibly easy to clean, often requiring nothing more than a simple wipe-down with a cloth. Keep these factors in mind when selecting your ideal BCG.
- Increased Speed
By opting for a BCG made of titanium or anodized aluminum, you can significantly reduce the weight and mass of your firearm, thereby enabling it to cycle at a faster rate in a semi-auto fire when compared to heavier steel counterparts.
Although the practice is key to achieving optimal weapon control, the increased rate of fire afforded by these materials can prove advantageous in competitive settings. Consider the potential benefits when selecting your ideal BCG.
- Improved Action Smoothness
BCG features a Nickel Boron, Diamond-Like Carbon, or Black Nitride coating, providing a slick surface and reduced friction that results in an overall smoother action. Selecting a BCG with these coatings can enhance the performance and longevity of your rifle, making it a valuable investment for avid shooters.
The Best AR-15 BCGs List
- Rainier Arms AR-15 Precision Match Grade BCG - Nitride
- Sons of Liberty Gun Works AR-15 Bolt Carrier Group
- Bravo Company MFG (BCM) Bolt Carrier Group
- Bravo Company MFG (BCM) Bolt Carrier Group - FLAT DARK EARTH-IB
- Andro Corp Industries AR-15 Enhanced Bolt Carrier Group (BCG) - Nitride
- JP Enterprises LMOS Small-Frame Complete Bolt Carrier Group - 6.8 SPC QPQ Black
- WMD Guns AR15 Bolt Carrier Group - NiB-X
1. Rainier Arms AR-15 Precision Match Grade BCG - Nitride
The Rainier Arms Precision Match Grade Phosphate BCG has been designed to meet and exceed all Mil-Spec standards.
One of the standout features of this BCG is the bolts, which are not only MPI/HP tested but also marked, providing the user with the utmost confidence in their weapon system.
This BCG is crafted using premium quality heat-treated SAE 8620 material.
The Nitride finish ensures that the BCG is highly resistant to wear and tear, even in the most demanding environments.
It's important to note that this BCG is a full auto carrier, which means that it is built to handle the rapid firing rates of automatic weapons. This makes it a great option for those who prefer to shoot in burst mode or enjoy the challenge of firing in automatic mode.
Price: $169.95
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2. Sons of Liberty Gun Works AR-15 Bolt Carrier Group
The Sons of Liberty bolt carrier group is machined from high-quality steel and is designed to exceed mil-spec expectations for reliability and longevity.
Also, every component has been heat-treated to ensure it won’t fail you during use.
The carrier is made of AISI 8620 aircraft-quality steel, the Carpenter Technology No. 158 Alloy is used for the bolt, and the gas key is made from 4130 Chromoly steel.
The BCG also features shot peening to improve strength, the precision ground gas key interface on the carrier to secure the gas key, and a solid film lubricant on the cam pin to reduce wear when the bolt is unlocking.
Price: $179.00
Purchase here!
3. Bravo Company MFG (BCM) Bolt Carrier Group
This one is a complete bolt carrier group. It’s machined to USGI specifications and features a Parkerized exterior with a chrome-lined interior, made to improve its durability.
The bolt assembly is machined of Carpenter No. 158 steel to Mil-Spec standards and includes a shot-peened design for increased strength.
Additionally, it includes a tool steel machined extractor and ejector, BCM Extractor Spring, and is both HPT and MPI tested.
All in all, this bolt carrier group is a great choice if you’re looking for a durable and reliable option for your AR15 rifle.
Price: $189.00
Purchase here!
4. Bravo Company MFG (BCM) Bolt Carrier Group - FLAT DARK EARTH-IB
This is a fully assembled, auto version bolt carrier group machined to exacting USGI specifications and features a rugged Parkerized exterior and chrome-lined interior carrier.
What sets apart this BCG is its Mil-Spec gas key - chrome lined and heat treated to GI specifications and secured to the carrier using Grade 8 fasteners properly staked to ensure optimal gas system functionality.
The bolt assembly is equally impressive, machined from the correct Mil-Spec Carpenter No. 158 steel and shot peened for increased strength.
Parts are properly hardened, which will surely maintain performance and strength even under the most demanding conditions.
Also, before shipping, these BCGs are test fired for function, ensuring that your new bolt carrier group is ready to perform right out of the box.
However, a rigorous testing process may leave some handling marks which is a small price to pay for peace of mind. Of course, if you’re comfortable with this.
Price: $199.00
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5. Andro Corp Industries AR-15 Enhanced Bolt Carrier Group (BCG) - Nitride
The Andro Corp BCG is another great part to consider. Andro Corp is already a well-known brand on the market.
The bolt is made of 9310 alloys while the carrier is crafted from 8620 alloys.
It also features Nitride coating and HP/MPI bolt (High-Pressure and Magnetic Particle Inspection). These testing methods are used to ensure quality and reliability so you’re safe with this one BCG.
Another thing worth mentioning is enhanced beveling which helps in friction reduction while an upgraded Viton O-ring extractor ensures reliable extraction every time.
And with its full-auto rating, this bolt carrier group is ideal for those looking to take their rifle to the next level.
Price: $108.92
Purchase here!
6. JP Enterprises LMOS Small-Frame Complete Bolt Carrier Group - 6.8 SPC QPQ Black
This one is a low-mass carrier, combined with a compensator that significantly reduces felt recoil and the movement of the rifle.
This results in faster sight recovery and follow-up shots, which is crucial in any shooting situation.
It has JP EnhancemetBolt included too which is proven to be better than those standard mil-spec bolts as it’s made of SAE 9310 that drastically increases the part lifespan.
Besides that, it’s compatible with any AR-15 platform using the mil-spec bolt carrier and sub-components.
However, there is one downside: it’s not compatible with .308 AR-type rifles.
In conclusion, it’s a great BCG providing less recoil, faster sight recovers, and follow-up shots. It is durable, efficient, and versatile.
Price: $375.25
Purchase here!
7. WMD Guns AR15 Bolt Carrier Group - NiB-X
The bolt on this one is made from case-hardened 9310 steel which has been shot-peened and magnetic particle inspected for maximum durability and reliability.
It comes with a high-performance extractor, ejector springs, gas rings, and a special O-ring buffer.
The extractor is manufactured, heat-treated, and hardened according to government drawings, and it's coated in NiB-X (nickel boron) for enhanced durability and reliability.
The firing pin is also manufactured, heat-treated, hardened, chromed, and certified according to government drawings.
The carrier is a faceted M4/16 style full auto (heavier) that functions in AR15 and M4/16 platforms. It's made from 8620 material, which is heat-treated and case-hardened.
The gas key is hardened to USGI specifications and attached using grade 8 hardened fasteners, and Permatex No. 3D Aviation Form a gasket Type III Sealing Compound per MIL-S-45180 is used on assembly. It's also coated in NiB-X and staked per military specifications.
Finally, the cam pin is manufactured, heat-treated, hardened, and certified according to government drawings, and it's coated in NiB-X for enhanced durability and reliability.
Price: $164.00
Purchase here!
Conclusion
When you look at just how important the bolt carrier group is in your firearm, it is hard to deny the fact that it should be the best, more durable part of the rifle.
Yes, it can add expense to your build, but it will add a lot of longevity to your firearm in the long run.
Why struggle with an unreliable weapon when you can just pick up a few things to make yours run better than ever? The phrase “buy once, cry once” may be overused at times, but it still rings true when you are considering upgrading your Bolt Carrier Group.
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