Finding the best AR-15 Bolt Carrier Group (BCG) is a tough task. Not only there are so many to choose from, but finding the right one for you will take more than just based on your personal needs.
Like the engine of a very nice sports car, your AR 15 needs a great bolt carrier group to improve the performance of your gun.
We will be looking at eight of the best AR 15 BCGs available on the market today. Your next one might be one of them.
Pay close attention to each review as they will have a unique feature or two that sticks out. That may drive you to make your final decision.
For those of you who can’t wait, here is my list of best AR-15 bolt carrier group (BCGs):
- Daniel Defense M16 5.56 Bolt Carrier Group
- Bravo Company M16 5.56 Bolt Carrier Group
- Brownells M-16 Mil-Spec MP/HPT Bolt Carrier Group
- Spikes Tactical M16 5.56 Bolt Carrier Group
- JP Enterprises AR-15 Low Mass Bolt Carrier Assembly
- JP Enterprises AR-15 Full Mass Bolt Carrier Group
- WMD Guns M16 NIB-X Bolt Carrier Group
- Anderson Manufacturing M16 5.56 Bolt Carrier Group
Best AR 15 Bolt Carrier Groups (BCG)
Daniel Defense M16 5.56 Bolt Carrier Group
Our first review is the Daniel Defense M16 5.56 Bolt Carrier Group. This BCG is made from carpenter 158 stainless steel. For added durability, the Daniel Defense features a shot-peened bolt. If you want reliable cycling while you're set to rapid fire, this BCG comes equipped with an extraction booster.
Every BCG manufactured by Daniel Defense undergoes a rigorous set of tests to ensure that their products are the most durable on the market.
To be more specific, this type of testing is known as MPI testing. And to prevent gas leakage, the gas key itself has been staked.
The Daniel Defense is compatible with full auto rifles thanks to the full-length shroud on the base. And it comes finished with a mil-spec phosphate matte black finish.
The Daniel Defense is easy to install, so you won’t need any special gunsmithing skills required for this kind of BCG.
- Matte Black finish
- Crafted from stainless steel and a shot-peened bolt for extra durability.
- Extraction booster for reliable cycling during rapid fire sessions.
- One of the best BCG’s on the market in terms of quality.
- Continues to function very well after hundreds of rounds.
- Fits perfectly with most ARs, including AR-15s.
- Some reviewers said that users should check for headspace before use.
- One reviewer complained that the finish is not as smooth.
The Bottom Line
Daniel Defense strives to be a reliable brand for AR-15 accessories like the BCG. Testing their products for durability before they are ready for sale is just plain smart on their part. The last thing they want to see is customers throwing away their money on BCGs that will not do its job, only to spend money on another. If you want a brand you can trust and a BCG to last you a long while, I highly suggest giving Daniel Defense a chance.
Bravo Company M16 5.56 Bolt Carrier Group
Next, we take a look at the Bravo Company. Like the Daniel Defense, this BCG is crafted with carpenter 158 stainless steel. This also has an ion bond coating on the outside and a chrome lining on the inside. The ion bond is also designed to make the operation frictionless. For added strength, the components of the BCG have been shot-peened. The Bravo Company undergoes all kinds of testing (MPI and HPT testing) to ensure the best in durability.
If you want a BCG that’s easy to clean, the Bravo Company may be your brand of choice. Also, the company claims to test fire their BCGs before they are sold. It’s easy to install and very pleasing in terms of aesthetics.
- Crafted with 158 stainless steel.
- Ion bond coated exterior for lesser friction.
- Tested for durability and overall usability.
- Some users were happy with the overall finish.
- No heavy wearing was present after 1000 rounds.
- Perfect for low weight ARs.
- One user complained that this was “kind of rough”. Unsure if this regards the finish.
- Some users have complained that their AR-15 started double feeding after firing approximately 20 rounds.
The Bottom Line
Bravo Company is one of the most reliable brands that most gun owners and enthusiasts that often speak highly of. They still do. If you’re looking for a BCG from a trusted brand, then you might like the Bravo Company. If their products are always tested, be it for quality or how it functions during use, then that’s a plus. Especially for the customer looking for the best AR-15 bolt carrier group.
Brownells M-16 Mil-Spec MP/HPT Bolt Carrier Group
Brownells is the next item on the list. While the bolt is made from 158 carpenter steel, the carrier itself is machined from hardened 8620 steel. This BCG is heat-treated, so it can withstand the high heat of AR-15 usage, even if you’re firing it on the range for an extended period. This is also shot-peened for the purpose of adding more strength. The gas screws are properly staked and torqued.
The Brownells claims to conduct its own MPI and HPT testing to make sure the BCG doesn’t warp, crack, or damage easily. However, since Brownells is one of the more reliable brands viewed by gun owners and enthusiasts, they’ll take it as it is. It may not matter to users that if it comes with a stamp or not proving that they’ve been tested.
To ensure extended service life and easy cleaning, the interior contains a chrome lining. This also has a mil-spec standard phosphate finish. This may explain why it is affordable than most BCGs on the market.
- Bolt machined from 158 carpenter steel, carrier is crafted from hardened 8620 steel.
- Gas screws are properly screwed and torqued.
- MPI and HPT tested.
- Fits very well with most AR-15s.
- Excellent return policy when you have a defect.
- Some users were very happy with the finish.
- Some users have noticed that the ejector spring weakens after 1850 rounds.
- Some users have complained that the bolt is difficult to move.
- Some have had issues with the firing retention pin.
The Bottom Line
Brownells might be the best brand for you if you’re looking for a low-cost replacement for your existing BCG. Thankfully, this works with many guns and may very well be compatible with your AR-15. One thing to note, despite the popularity of a brand, you should always take whatever claims a company makes with a grain of salt.
Companies can say that their BCGs have been tested and will slap on a sticker proving that. Brownells, from what I know doesn’t do that. That could probably be due to the brand itself is easy to trust when it comes to making quality products (i.e.--”Well, because it’s Brownells”).
Spikes Tactical M16 5.56 Bolt Carrier Group
The Spikes Tactical is a BCG that is made from some of the best materials to ensure that it becomes one of the strongest on the market.
The Spikes Tactical is crafted from 158 carpenter steel and also from 8620 carbon steel. If a BCG is created with materials like these, you know for sure that it will be as strong as it gets.
The Spikes Tactical is a full-auto bolt carrier group.
The inside has a chrome lining. If you’re also looking for an aesthetically pleasing BCG, you might be satisfied with the Spikes Tactical. The finish is a standard mil-spec phosphate finish on the outside. This also features a staked gas key and is MPI tested. This is one of the best BCGs for those who use their AR-15 for hunting and target practice.
- Crafted with carpenter steel and carbon steel for the best in durability.
- MPI tested.
- Staked gas tech key.
- Continues to function perfectly after 500 rounds.
- Works perfectly for the value it is worth.
- HP and MP tested at the factory.
- Might need to be cleaned before installation as it is covered in a sticky yellow grease.
- May come dirty due to test firing.
- Some have complained about missing “Made In The USA” stickers or missing logos.
The Bottom Line
It's surprising to see that a BCG that is affordable given that one of the materials it's made from can be expensive. So, if you can swing the price of this BCG, it will be a steal in your point of view. Just remember, the BCG is the heart of your AR-15. If you want one that is durable and will last you a long time, you might be satisfied with the Spikes Tactical BCG.
JP Enterprises AR-15 Low Mass Bolt Carrier Assembly
This is a low mass/lightweight BCG. This is manufactured from 416 stainless steel and has a lower reciprocating mass. This is also a BCG that is designed to reduce recoil impact. If you’re using your AR-15 for competitive purposes, you’ll probably want a BCG like this. This also has a dust cover notch and a staked carrier key. In order for this BCG to work more effectively, you’ll need to use low-mass components that are compatible with it. Once again, this is a BCG that is the best if you’re a competitive shooter.
- Crafted from 416 stainless steel.
- Comes with a dust cover notch.
- Carrier key installed.
- Perfect for competition shooters.
- No major wearing after 1000 rounds.
- Does not have forward assist. Which is good for competitive shooters.
- Not for the average shooter.
The Bottom Line
At this point, it may sound a bit repetitive, but this is the BCG that stands out for competition purposes. It may not fit very well for other uses like for hunting or home defense. This is a prime example that not all BCGs are created equal. One is perfect for a specified purpose while others can be served for multiple purposes.
If you’re a shooter that is looking for a best AR 15 bolt carrier group that will make sure you stay on top of your game during a shooting competition, you might be very happy with the JP Enterprises Low Mass BCG.
JP Enterprises AR-15 Full Mass Bolt Carrier Group
Of course, we shouldn't exclude the full mass version of this JP Enterprises BCG. This is made of stainless steel. This also has a superior quality quench, polish, quench nitride finish. This finish will ensure that the BCG is resistant to corrosion and also gives it increased lubricity and hardness. This also includes an extended forward assist serration and a dust cover notch. In short, it strives to be a more versatile, high performing BCG.
When properly lubricated, this high-quality BCG will make your AR-15 run like a dream. This might be the best AR BCG on the market and may not disappoint you in certain regards. The design and the high quality is what makes this BCG stand out. But does it stand out in terms of your personal needs?
- Extended forward assist serrations and dust cover notch.
- Polished surfaces.
- Very reliable operation.
- Some users say that the performance is unmatchable compared to other BCGs.
- Cleans up pretty easy and quick.
- Glides through the upper receiver with little to no resistance.
- Not an ideal BCG for competition purposes. That purpose is best used for the low mass version.
The Bottom Line
If you’re looking for a high performing BCG, chances are you might find it with the JP Enterprises Full Mass Bolt Carrier. It’s incredible engineering and design alone might make this one of the more popular choices for gun owners and enthusiasts. This BCG is based on years of shooting and engineering experience to give users every advantage of a mil-spec BCG and then some. If that’s something you look for, then this BCG might stick out as a favorite of yours.
WMD Guns M16 NIB-X Bolt Carrier Group
WMD Guns provides what appears to be the only nickel boron BCG that will be a part of this review. Not only that, it is proven to be harder than other materials like nickel Teflon, melonite, or hard chrome. At this point, you know that this is going to be one tough customer. Even better, it's resistant to corrosion. Performance wise, you expect this to cycle smoothly with every round. It will also provide longer cycles without any stoppage.
This is a drop-in BCG that fits perfectly with any AR-15. Like any tough, durable gun part, it comes backed with a lifetime warranty. Plus, it’s easy to clean and requires less maintenance.
- Made from nickel boron for superior durability.
- Slick finish to keep carbon from adhering.
- Very easy to install and clean up.
- Gas rings fit nice and tight.
- Still cleans up and runs smoothly after 500 rounds.
- Very smooth cycles, even after so many rounds.
- Some reviewers complained about discoloration after using it for a while.
- Some users have complained that the recharge is not as good as it’s supposed to be.
- Cleaning may be a little bit more than just wiping down.
The Bottom Line
So far, this is one of the most durable BCGs that we’ve reviewed. Not only do you get very good durability, but the performance is pretty stellar as well. If you’re looking for a best AR-15 bolt carrier group and fit in the “this is the last BCG I’ll ever buy for awhile” camp, you should consider getting this one. Even some reviewers have said that even after 100 or more rounds, this puppy can really hold its own. The main thing to note to make sure this lasts you a long time is to clean it regularly (preferably after each shooting session).
Anderson Manufacturing M16 5.56 Bolt Carrier Group
Lastly, we will be looking at the Anderson Manufacturing M16 5.56 BCG. The bolt is made of 9310 steel and the carrier is made from 8620 steel. This also comes with a phosphate finish. Of course, it is easy to install considering that it is a drop-in BCG. Both the bolt and carrier are MPI tested. The extractor includes an o-ring insert to ensure positive extraction.
Anderson is considered to be one of the top manufacturers for BCGs designed for M16s, but this one, in particular, can also fit very well with most AR-15s. This is designed to make your firing your rifle as simple as possible.
- Crafted from 9310 steel (bolt) and 8620 steel (carrier).
- MPI tested.
- Matte black phosphate finish.
- Works in full auto for semi-automatic AR-15s. So the pin is shrouded.
- Very durable.
- Shoots great after several rounds.
- The staking on the gas keys may need adjustment.
The Bottom Line
If you’re building an AR-15 on a budget and want a BCG that will still work without any issue after several hundred rounds, you won’t be disappointed with something like the Anderson Manufacturing BCG. You’ll want a BCG that functions smoothly and will still continue to do its job every time you use it.
What To Look For In An AR-15 Bolt Carrier Group
If you’re in search of the best AR-15 Bolt Carrier Group, you have to know what you’re looking for. You can’t simply just grab one off the shelf or buy one online on a whim. Some of the other factors will play a role in choosing the right one for you. Here are what some past buyers have said about what played a role in their purchase:
Obviously, the material is the first thing that you should consider. BCGs are often made of steel. However, others that are available are made from materials like aluminum, titanium, or even hybrids of these materials. The most common materials that are used for manufacturing BCGs are 9130 and 158 carpenter steel.
These steel variants fit very well since BCGs deal with a lot of heat and stress. This type of steel is widely available and also easy to machine. Of the two, most manufacturers have opted to use 9310 for crafting their BCGs. Carpenter 158 steel is used by the military, so any BCG crafted from this type of steel is considered military grade. Aside from being water resistant, it is also high in core strength and hardness.
Heat Treatment And Shot Peening
Any material used for the manufacturing of BCGs must be treated properly and processed to ensure optimum performance. Heat treatment is when the steel is subjected to high temperatures and then cooling it to remove fatigue and impart tensile strength. Shot peening is a process where tiny metal balls are shooting at the steel. Its purpose is to relieve the stress of the metal.
Any BCG that has undergone heat treatment and shot peening successfully is an excellent sign. This means that the BCG is durable and will be a part of your AR-15 that will function properly for a long time.
Inner Chrome Lining
The BCG group must be lined on the inside with chrome. This is in accordance with mil-spec requirements. This is to ensure that the inside is smooth and resistant to corrosion. In turn, this also ensures that the BCG life expectancy is extended. Also, it makes it easy to clean when the time comes. It should be noted that most manufacturers line the BCG on the outside, not the inside. You should consider getting a BCG with a chrome lining that is inside if you want a longer lasting unit.
Every time your rifle is fired, the BCG undergoes enormous gas pressure. The gas key is secured to the carrier so gasses are prevented from escaping. The keys are usually secured using two hex screws.
The screws are staked so they cannot move due to the gas pressure. This prevents accidents and failures.
HPT and MPI Tested
Manufacturers test their BCGs using two rigorous tests. The purpose of these tests is to ensure the quality and reliability of their product. This will also give them the opportunity to see if any defects exist. These testing methods are known as the HPT (high-pressure testing) and MPI (magnetic particle testing).
In an HPT, a high-pressure cartridge or higher than normal service loads are fired from the BCG. It will also undergo further inspections to detect any wears, malfunctions, or cracks in the metal.
In MPI, the bolt is placed between the poles of an electromagnet. It is then covered with magnetic particles. Finally, the manufacturers will inspect the BCG with a UV light to inspect for any wears or malfunctions.
Checkout some useful resources:
How the AR 15 Bolt Carrier Group Works:
How to disassemble an AR 15 bolt carrier group:
AR15 vs M16 Bolt Carrier Group Comparison:
Full Auto vs Semi-Auto Bolt Carrier Groups
Finding the best AR-15 bolt carrier group doesn’t need to be a challenge. It’s important to find one that will last you a long time without having to waste any money ever so often. Find one from a brand you know and trust. You can also do further research if one BCG in particular sticks out as the best.