6 Sweet 6.5 Grendel BCGs for A Smoother Running AR

Michael Crites

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Various types pf bolt carriers

This article is part of our Guide to Everything AR

The 6.5 Grendel is a flat shooting round with little recoil, so many shooters are switching to this caliber in their ARs. However, to change to this caliber, you need to change the upper, including the bolt carrier group (BCG).

What are the best 6.5 BCGs? I’m glad you asked because we compiled this list to help you choose the one that best fits your situation.

In This Article:

6.5 Grendel BCG Comparison

Below is my list of the recommended 6.5 Grendel bolt carrier groups. I list the best choices in terms of value, performance, design, and cost.

Click on the name to head to the product page, read reviews and check prices or skip ahead to the list of BCGs.

Why you should listen to us

Firearms have been an essential part of my life for as long as I can remember. I have countless cherished memories involving guns with my grandfather, father, and friends. However, the first time I shot a gun, I didn’t love it. I was small, and I didn’t like the recoil. It didn’t take long to try again, and my dad was smart enough to downsize to a smaller caliber with low recoil.

I was hooked once I realized recoil wasn’t anything of which to be scared. Since then, I’ve spent years shooting and hunting with various firearms and calibers. When I’m not outside, I’m in my shop tinkering with and studying guns.

6.5 Grendel BCG Recommndations

1. Odin Works 6.5 Grendel Type 2 Bolt Carrier Group

Odin Works manufactures aftermarket gun parts, primarily for the AR-15 platform. They’re one of he first brands many AR builders turn to because they offer a solid mix of quality and price point — plus they have a huge selection of components to choose from — low-profile gas blocks, mag releases, upper receivers, charging handles, bolt carrier groups, etc.

The Odin Works 6.5 Grendel Type 2 BCG is durable because it’s constructed from high-quality materials. The bolt is precision machined from case-hardened 9310 steel, the gas key is 4130 steel, the shrouded firing pin is hard-chrome-plated 8740 steel, and the extractor is 4340 steel. The bolt carrier group has a black nitride finish.

This bolt carrier group is designed for the 6.5 Grendel Type 2, so if you want a Type 1 6.5 Grendel BCG, I don’t recommend this product. The Odin Works BCG is proudly made in the USA and, when purchased from Brownells, has a Forever Guarantee*.

The Odin Works 6.5 Grendel Type 2 Bolt Carrier Group is for anyone building a Type II 6.5 Grendel AR-15 that prefers American-made products.

2. Brownells M16 6.5 Grendel BCG

Brownells is a major online retailer fo gun parts, gunsmithing tools, and other firearm-related gear plus their house brand of aftermarket parts. They’ve been “serious about firearms since 1939” — and they mean it — if you need a part for your weapon, chances are they make it or sell it.

The Brownells M16 6.5 Grendel BCG is constructed from two distinct types of steel. The bolt is 9310, and the carrier group is 8620 hardened steel. It’s shot-peened, heat-treated, and magnetic particle inspected to ensure a reliable, smooth operation.

This is a Type II bolt with correct gas-key torquing and staking. It has a nitride black finish for corrosion resistance. The Brownells bolt carrier group includes the bolt carrier, gas key, firing pin, cam pin, and retaining pin for the firing pin at an affordable price.

If you’re building a Type 2 6.5 Grendel AR-15, then this bolt carrier group offers excellent performance at an affordable price.

3. Aero Precision AR-15 6.5 Grendel BCG

Aero Precision is one of the most popular lower manufacturers in the game today with their upper receivers, complete lowers, and bolt carrier groups garnering almost universal acclaim for their build quality.

This Type 2 bolt carrier has several features to satisfy many gun enthusiasts. It’s an M16 cut bolt carrier that is compatible with AR-15s. The carrier is machined from 8620 Tool Steel, and the bolt is machined from 9310 steel. The black nitride finish is a lower friction coating that minimizes the need for gun lube and cleaning.

The carrier has forward assist serrations that help ensure a secure fit. It has a properly staked gas key, o-ring insert on the extractor, and has been shot-peened to make it stronger.

Whether this is your first AR build or your 100th, the AERO Precision AR-15 6.5 Grendel Bolt Carrier Group is a high-quality product at a reasonable price. If you plan to get the needed permits and parts for a fully automatic M16, then you’ll need this one or another M16 bolt carrier group.

4. Faxon Firearms M16 BCG in 6.5 Grendel

Faxon Firearms is renowned for its barrels and quality firearm parts, including bolt carrier groups. They primarily focus on AR-15 parts for different calibers, but they have barrels for pistols and rifles.

The Faxon Firearms M16 6.5 Grendel BCG is a Type II bolt carrier group made from 9310 heat-treated Tool Steel, shot-peened to MIL-Spec, and received magnetic particle inspection (MPI).

This bolt carrier group is full-auto compatible, but that doesn’t mean it will make your AR full-auto. You will still need to buy other parts and permits for fully automatic capabilities. The black nitride finish enhances the corrosion resistance.

The Faxon Firearms 6.5 Grendel Bolt Carrier Group offers exceptional performance for firearms enthusiasts looking to build a fully automatic M16.

5. JP Enterprises AR-15 6.5 Grendel BCG

JP Enterprises primarily specializes in AR-15 parts in various calibers like an AR-15 rifle spring kit or Bolt Carrier Kits that are all highly rated by customers.

The JP Enterprises BCG is precision-machined high-grade 9310 steel, giving it a longer lifespan than standard Mil-Spec bolts. It also has an increased bearing surface that offers smoother cycling and less wear on the inside of the upper receiver.

The JP Enterprises AR-15 BCG offers a hard QPQ finish for more wear resistance and less friction. It is preferred for duty and competition rifles because of its reliability.

The JR Enterprises AR-15 6.5 Grendel/ 6MM ARC Full Mass Bolt Carrier Group works with both calibers, so if you plan to use either one, you can. However, it homes at a higher price than others on the list, so if you’re on a tight budget, this isn’t the BCG for you.

6. PSA 20" 6.5 Grendel Upper

If you’ve spent any time online researching AR components you’ll have come across Palmetto State Armory. They’re a major player in the online firearm parts and accessories game. They also manufacture gun parts such as 6.5 Grendel bolt carrier groups and uppers.

Yes, this is more than just a bolt carrier group. It includes the upper (complete with barrel), BCG, and charging handle (CH), so for the price, it’s tough to beat, considering some BCGs nearly cost this much alone. The carrier is crafted from 8860 steel and nitride treated. The bolt is 9310 steel shot-peened, while the gas key is hardened and staked per Mil-Specs.

Because the bolt carrier group is an M16 profile, it has full-auto capabilities. Since this upper comes with the BCG and CH, you can trust that the parts will fit and have a proper function.

The PSA 6.5 Grendel Upper with BCG & CH is for the gun enthusiast that doesn’t want to purchase all the parts separately to build a quality AR.

History of the 6.5 Grendel

After several variations, the 6.5 Grendel evolved from the Soviet 7.62×39 primarily on the European shooting competition circuits. People experimented with a new caliber size for flat shooting with less recoil for years. The 220 Russian, 22 PPC, 6mm PPC, and the 6.5 PPC were all predecessors of the 6.5 Grendel, but they all lacked in some form or fashion.

Finally, in May of 2003, the new round 6.5 Grendel was unveiled. It outperformed the 7.62 NATO that day and has continued outperforming other comparable lead rounds. It’s an excellent round for long-range shooting when you need little recoil because of how flat it shoots.

Why Swap Your BCG?

Charging handle, Bolt carrier group , Completed upper receiver
If you're building an AR or just particular about performance, you'll need the right BCG.

There are a couple of instances when you will need to change your bolt carrier group, and there are other times when you would be wasting your money upgrading your BCG.

Let’s discuss both!

If you have a high-end rifle with a budget BCG, you need to upgrade to experience all the benefits of a high-quality gun. Another time you need to purchase an improved bolt carrier group is if you want to make your AR fully automatic. You will need the legal permits and a firearm capable of full-auto for it to work. Swapping out the BCG will not turn your gun into a fully automatic weapon unless it’s designed to be one.

If you only upgrade the bolt carrier group on a budget rifle, you will waste your money. If you own a budget rifle, the BCG will not improve its performance enough to notice a difference. So save up for a quality rifle instead of trying to turn a cheap rifle into an expensive one.

Must-Have 6.5 Grendel BCG Features

While everyone has their preferences, most can agree that bolt carrier groups should have the following features to ensure safety, reliability, and durability.

Quality Materials

We always want high-quality materials in our products, but it’s crucial for firearm parts. After all, we’re dealing with controlled explosions, so these aren’t the components to skimp on or worry much about weight savings. It’s also why high-grade steel is a must.

Even better if it’s been high-pressure tested, shot-peened, or heat-treated, as these processes make the steel less likely to fracture.

Passed Tests

BCGs are under extreme stress with every shot. A single point of failure — even a hairline crack — creates vulnerability in the material that can lead to a catastrophic failure. Tests that highlight flaws in the material, like imperfections and cracks invisible to the naked eye, are critical for ensuring the product will stand up to the abuse you’ll throw at it on any range day.

A quality bolt carrier group will pass and be certified with both high-pressure testing (HPT) and magnetic particle inspection (MPI) tests.

Magnetic Particle Inspected (MPI)

MPI testing highlights imperfections in the metal, ensuring there are no cracks or flaws once passed.

MPI inspection involves placing the product in a liquid solution containing magnetic particles between two electromagnets. 

If these particles stick to any part of the bolt carrier group when a magnetic field is applied, it highlights a potential imperfection.

Adjustable Gas Key

An adjustable gas key allows you to regulate gas pressure directly at the bolt carrier group — enabling minor changes so that the gun cycles smoothly without the need for disassembly.

If you’re having trouble with your AR not cycling correctly, you can adjust the gas key to improve performance.

Want to head down the gas system rabbit hole? Take a dive into our gas system guide!

Corrosion Resistant Finish

Nickel Boron BCG
Nickel boron increases a metal's lubricity or friction reduction.

Corrosion can, and will, ruin a good firearm. That’s why we have so many different processes and materials that are less likely to corrode.

Most BCGs have a black nitride finish which is corrosion resistant; stainless steel is also naturally resistant to corrosion. Remember, resistance doesn’t mean it can’t rust; it’s just unlikely to unless you abuse it.

High-Pressure Testing (HPT)

HPT follows MPI testing, and involves firing an excessively high-pressure cartridge (beyond SAAMI-rated specifications for the test cartridge) through the BCG to verify its durability.

Bolt Carrier Group or Just the Bolt?

Changing the BCG is much simpler than changing the bolt as you’re more likely to find the complete bolt carrier group than just a bolt. It’s also more cost-effective buying the whole assembly compared to purchasing each part individually.

Components of a 6.5 Grendel BCG

BCG Components
Bolt carrier groups are made up of many components.

A bolt carrier group is comprised of a number of small parts. Be it an AR-15 5.56 BCG, AK 7.62×39 BCG, or a BCG for your 6.5 Grendel, they’re all pretty similar.

The caliber-specific component is the bolt, but most of the pieces you’ll be familiar with from one caliber to the next.

The BCG will only function if all of the component pieces are in good working order, so I always recommend picking up a parts kit, because breakage is not a matter of if, but when.

The following are the components of a 6.5 Grendel BCG:

  • 6.5mm Grendel Bolt
  • Firing Pin
  • Firing Pin Retainer Pin
  • Gas Key
  • 2 Key Screws
  • Bolt Cam Pin
  • Extractor
  • Extractor Pin
  • Extractor Springs
  • Extractor O-Ring
  • Ejector
  • Ejector Spring
  • Gas Ring
  • 1/16″ Roll Pin

Types of 6.5 Grendel BCGs

Various types pf bolt carriers
BCGs come in a few flavors -- one of which being low-mass (top) which reduces amount of material flying around with each shot, and can provide a unique opportunity to dial in a rifle to specific preferences.

There are two types of Grendel bolt carrier groups, conveniently named Type 1 and Type 2. Type 1 has a bolt depth of 0.125, whereas the Type 2 bolt has a bolt depth of 0.136. These differences came about because of copyright and patent issues.

The differences in bolt face depth, neck depth, and taper shape account for the need for different sizes of extractors to get rid of the spent casing. Most BCGs listed above are Type two. 

There are also AR-15 bolt carriers and M16 bolt carriers. The main difference between these two is that AR-15 bolt carriers are semi-auto only, whereas M16 bolt carriers can be a semi-auto or a full-auto carrier.

M16

M16 vs AR bolt - full auto vs semi auto
Both are legal, but one can get far more thirsty.

An M16 BCG has a third trigger pin hole, which allows the auto to function in full-auto. These BCGs have more material at the rear of the carrier, called a gull auto lugm which is necessary for the rifle to function in full auto.

There are no legal ramifications for using an M16 bolt carrier group in an AR-15 because the BCG itself does not enable fully automatic fire.

An M16 lower configuration, however, is regulated to prevent it from being assembled in a way that allows for full auto firing. 

Low Mass

Brownells example of a Low Mass BCG
Brownells example of a Low Mass BCG

There are a number of benefits to low-mass bolt carrier groups, which were developed to reduce the BCG’s mass and lighten a rifle’s build.

 This reduction in mass means softer felt recoil, which can be dialed in further with spring and buffer system optimization.

Beyond building a more approachable rifle, low-mass carriers will often be found in competition rifles. Softer recoil means a more controllable firearm — one that can be brought back on target faster, which is critical when navigating timed courses, placing precision long-range shots, or making follow-up shots.

Price Ranges vs. Features

  • $150-$300. For around $150, you will find good-quality bolt carrier groups that have everything you need. You won’t have to search for bolt assembly parts at this price range unless you don’t like the one that comes with it. You shouldn’t expect to get incredibly high-performance out of these BCGs because this is the entry-level price range, so expect entry-level quality.

  • $350+. When we enter this price range, we have stepped up into the higher-quality materials to expect better performance from these bolt carrier groups. The QPQ or Quench-Polish-Quench finish, which some of the BCGs have in this range, is superior to other finishes like hard chrome or nickel plating because of its increased strength against corrosion and wear.

As with most things, you’ll always pay a higher price for better quality.

How we selected our recommendations

We prefer hands-on reviews, but due to financial restraints, that’s not always possible. Instead, we leaned on personal firearms experience, online reviews, & discussions with experts to hone in on the best of the best bolt carrier groups.

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