Carbon fiber components are the newest hotness in the firearms community. Some individuals like it for the aesthetics, while others like it for the actual, or sometimes perceived, reduction in component weight. Like most things, carbon fiber has its advantages and disadvantages when used in the construction of firearm components.
What are some advantages?
• Reduction of weight in correlation to size
• Thermal conductivity
• Rigidity
What are some disadvantages?
• Price
• Rigidity and component flexing concerns
o Carbon fiber needs to be the same weight as steel to maintain or exceed the rigidity of steel
• Brittle
• Larger diameter required to retain the rigidity that is similar to, or equal to, that of a steel or aluminum component
• Consistency in manufacturing
• Thermal conductivity
What is Carbon Fiber
At its core, carbon fiber is an inert material. An inert material does not react with other materials or substances under normal conditions. As it pertains to carbon fiber, carbon fiber doesn’t expand or contract like other materials. Other examples of inert materials are brick, concrete, some plastics, and some metals such as gold and platinum.
In industrial processes inert materials are used to support and carry catalysts. Substances that increase the rate of a chemical reaction without itself undergoing a permanent chemical change. If you’re familiar with chemical bonding agents such as JB Weld, two part epoxies, and automotive body filler, you have a base chemical that has a specific quantity of catalyst added to it to allow it to harden after application. In bonding agents, this change in the chemical process is what holds the two items together. Or bonds them.
It is a similar concept to the catalyst used in cerakote. The catalyst speeds up the curing process of the coating. This allows it to reach its full performance properties faster. It also has an effect on how glossy the final product looks after the curing process. This is done by adjusting the ratio of the catalyst. An example of this is the BRD black that is used on rifles where a client wants the rifle all black.
Carbon fiber is also known as graphite fiber. It is a lightweight, strong, and stiff material that is made from thin strands of carbon. It’s not until it is permeated with a resin compound and baked that it forms carbon fiber.
Thermal Conductivity
Carbon fiber as used in firearm components, does not conduct heat or cold well. It tends to be an insulator of heat and not a dissipater. This is why it’s commonly believed that a carbon fiber barrel dissipates heat quicker than a steel barrel. When temperature readings are taken with an IR temp gauge or a barrel attached temp gauge, these readings are surface temperatures. Being that carbon fiber has a lower thermal conductivity than steel, the heat from the barrel core below the carbon fiber has not yet reached the surface. It’s staying in the barrel core longer. Hence the lower surface temp. We will get into this a bit more when discussing barrels.
Barrel, handguard, and other manufacturers of carbon fiber components for firearms use their own proprietary resins in the application of carbon fiber. Some barrel manufacturers have been adding aluminum in their carbon fiber layers to aid in increasing the heat sink capabilities of the carbon fiber and barrel. Not all manufacturers do this, though.
Carbon Fiber Handguards
Reduced thermal conductivity of the carbon fiber can be experienced in colder or hotter environmental conditions. More so in colder conditions. This is a benefit that some individuals like and will seek in carbon fiber handguards and grips. If you take a rifle with an aluminum handguard and one with a carbon fiber handguard and set them outside in colder environments for the same length of time, you will find that the aluminum handguard will be colder than a carbon fiber. As the outside temperature drops significantly, especially below freezing, a greater difference between the two handguard materials will generally be greater. This is why some individuals that reside in colder climates prefer to have a carbon fiber handguard.
Now for a subject that most individuals don’t consider, and to be honest, isn’t a real concern when discussing predator hunting rifles, but that is the ability of a carbon fiber handguard to act as a heat sink. We’ve already established that carbon fiber in firearm components is not a good conductor of heat. We know that aluminum is a good conductor of heat. As a barrel heats up from extended use, an aluminum rail enables efficient heat dissipation from the barrel to the handguard through radiant heat. This can prolong shooting sessions as well as aiding in maintain consistent barrel performance. We do not get this advantage with a carbon fiber handguard, but the carbon fiber handguard does have the advantage of the handguard not heating up under such use. Making it cooler to hold than an aluminum handguard.
As you may be able to deduce by the above talking points about carbon fiber handguards and about the overall thermal conductivity, that carbon fiber has its advantages and disadvantages as it pertains to thermal conductivity.
Let’s touch on rigidity and weight, as it too, is an advantage and disadvantage when discussing carbon fiber use in handguards. We will deep dive this a bit more when discussing barrels, but it does have both positive and negative influences on handguards.
Like with barrels, carbon fiber needs to be the same weight as an aluminum handguard to have the same rigidity as the aluminum handguard. This results in a carbon fiber handguard that is a larger diameter than a respective aluminum handguard. Depending on the manufacturer, this difference can be great. This can create a hindrance to the shooter in the ability to use the handguard when shooting, as the diameter is large enough that doesn’t fit the average hand size well. This larger diameter can also create transportation or storage concerns due to the large diameter of the carbon fiber handguard. In addition, the use of a larger diameter carbon fiber handguard comes with a larger attachment system to attach the handguard to the upper receiver. The combination of both of these, commonly ends up with a carbon fiber handguard that is heavier than some quality aluminum handguards. So there is no weight savings, but there can be a weight gain.
Large Frame AR handguards. Pro & Nyx rifle handguard on the left & Lancer LCH7 on the right.
On the opposite end of this are carbon fiber handguards that are the same diameter, maybe a little smaller in diameter, than an aluminum handguard. While these handguards will generally have a weight savings as compared to the aluminum counterpart, they are generally thinner and less rigid. This leads to flexing of the carbon fiber handguard under pressure. An example of this is when you add an ARCA mount to the M-LOK rail. Dependent on the design and shape of the carbon fiber handguard, when you load the gun on a tripod to take a shot, these handguards will flex at the M-LOK mount due to the thinner cross section. As compared to aluminum or larger carbon fiber handguards.
There are many manufacturers of carbon fiber handguards. Some may only produce handguards for the AR-15, while others produce handguards for both the AR-15 and large frame AR rifles.
The two most common carbon fiber handguard manufacturers that are seen on predator hunting rifles is Lancer and Smoke Composites. These are also the handguards that have been used on the BRD Gun Works Carbon and Elite rifles. Handguards from these two manufacturers greatly differ in both design and size.
The Lancer carbon fiber handguards are approximately 2.2” in outside diameter and are octagon in shape. The Lancer handguard uses a large aluminum housing that screws onto the receiver extension for attachment of the carbon fiber handguard. The barrel nut screws into this housing to secure the barrel. The Lancer LCH7 16.25” handguards were used on the Invictus Carbon and Elite rifles. With the housing adaptor, the handguards weighed in at 15.1oz. Compare this to the 16” ultra-lite handguard that is used on the Invictus Pro rifle that weighs 12.3oz with the barrel nut. The ultra-lite handguard is 3.1oz lighter, and in testing and R&D, we’ve found the ultra-lite handguard to be more rigid than the Lancer LCH7. The ultra-lite rail measures 1.75” in diameter which is about a .5” less than the Lancer LCH7.
16.25″ Lancer LCH7
16″ Ultra Lite used on the Pro and Nyx rifles
The Smoke Composite handguards are much smaller in diameter than the Lancer handguards. They’re also much thinner. While the smaller diameter provides for a handguard that is easier to grip, and aids in storage and transportation, it is less rigid than the Lancer and aluminum handguards. Making it prone to flexing under load when shooting off of an ARCA mount. The diameter of a large frame AR handguard is 2.12”, while a 15” handguard weighs 8.5oz with the barrel nut. In comparison to the ultra-lite handguard as mentioned above, the Smoke handguard is 3.8oz less than the ultra-lite handguard, but it is also much less rigid. A down side to carbon fiber is that it is more brittle than a substrate such as aluminum. I’ve used a number of Smoke Composite handguards. Some on PCC competition rifles and some on predator hunting rifles. They flex. I have cracked more than one. Smoke Composite now makes their own ARCA mount that is specifically made to the contour of their handguard. We’ve used a few on the smoke handguards, and while it’s a huge improvement, it still doesn’t have the same rigidity of a Lancer or aluminum handguard. That said, I wouldn’t use a Smoke handguard without using their ARCA plate. At the time of this writing, their ARCA plate is $89.00.
Carbon Fiber Barrels
I think it’s important to clarify that carbon fiber barrels are not entirely carbon fiber. It’s a misconception by a lot of individuals that they are. To include into this, some carbon fiber barrels use less carbon fiber than one may think. It’s dependent upon the barrel design.
A carbon fiber barrel starts life as a standard barrel blank. We’ll use 416R stainless steel, as that’s what is used the most in carbon fiber barrels. This blank is then machined and profiled down to the barrel core dimensions as specified by the barrel manufacturer. From here, there are a couple of ways to go. The most common is the traditional way of carbon wrapping a barrel. When carbon wrapping a barrel, manufacturers use a resin to adhere the carbon fiber layers. This resin is generally proprietary to the manufacturer. These carbon fiber layers are feed from a spool to the barrel as it spins. Some manufacturers will add enhancements to their carbon fiber layers. Proof Research is one, and they add pieces of aluminum which they state aids in thermal conductivity and increasing heat transfer.
The other is the installation of a tensioned sleeve over the profiled barrel. Generally these are carbon fiber and do not contact the profiled barrel. Creating an air gap that is said to enhance cooling. Some barrels done this way also have vents machined into them to allow air to circulate between the sleeve and the profiled barrel underneath.
A number of years ago, Proof Research barrels were made for them by Bartlein barrels. Many don’t know, but Bartlein barrels has been doing work with carbon fiber barrels for a long time. One of the many things that they found out is that carbon fiber barrels need to be the same weight as a 416R barrel to maintain or exceed the rigidity and performance of the 416R barrel, and is one reason why they’re of a larger profile. This results in a significantly larger diameter than the smaller, more standard, profile of a 416R barrel of the same weight. This size of carbon fiber barrel is not practical. What we find with the larger diameter profile barrels from Proof Research, Carbon 6, and some others is a heavier profile carbon fiber barrel that will provide a weight reduction of a .5lb to around 1lb depending on the profile and manufacturing process as compared to a 416R barrel of similar profile. Here’s an example with the Carbon 6 243 Win barrel that I’ve used a lot of. A 20” 243 Win C6 barrel with rifle +2 gas length, .875” gas block journal, and a 5/8×24 thread weighs 2lbs 13.2oz. The BRDGW 22” 22CM heavy profile fluted barrel with rifle +2 gas, .875” gas block journal, and a 5/8×24 thread weighs 3lbs even. The C6 243 Win barrel with less bore material due to bullet diameter and 2” shorter barrel length, only saves 2.8oz over the longer and smaller bore diameter (more material) of the 416R 22CM.
Carbon 6 20″ 243 Win .875″ gas block journal
Carbon 6 20″ 243 Win .875″ gas block journal
BRDGW 22″ 22 Creedmoor heavy profile fluted 416R barrel
The heavier profile also has an added benefit when adding a suppressor. A suppressor will change the vibration of the barrel, which can have an effect on accuracy and precision. Even a titanium suppressor will do this. Without a deep dive into this, its principal is very similar to Browning’s old BOSS muzzle device, or barrel tuners that are currently seen in F Class shooting as well as some other shooting sports. A heavier suppressor will have a different effect than a lighter suppressor. This is where barrel profile comes in. Barrel whip is real. This is tied to barrel vibrations. One last thing on this. Some 416R barrels are too small of a profile to mount a suppressor to without heavy machining modifications. A carbon fiber barrel with a larger profile can allow for the mounting of a suppressor, without the added weight of increasing the barrel profile of a 416R barrel.
You will find carbon fiber barrels in various profiles. Some manufacturers offer carbon fiber barrels in a few different profiles that do not correlate to the sizing of a 416R barrel, while other manufacturers are all about cutting the weight and therefore producing carbon fiber barrels that are a much smaller profile than other carbon fiber barrels.
In our experiences with the small profile carbon fiber barrels, you can cut a significant amount of weight over a 416R barrel, but it comes at a cost. Generally, a barrel that is less rigid. One that heats up quickly and doesn’t dissipate heat as well. And a barrel that will generally open up or walk sooner than a 416R barrel or a heavier profile carbon fiber barrel. Machining can also introduce concerns to the internal bore of the barrel to include but is not limited to increasing the curvature of the bore. Introducing stresses due to the machining process. And machining the exterior of the barrel can open up the inner bore diameter. These can be more pronounced when greatly decreasing the external barrel diameter for a carbon fiber barrel.
Carbon fiber barrels have a tendency to open up in group size and/ or string shots before a 416R barrel will. There is nothing that dictates how soon or within how many shots this will happen. There’s a number of factors that go into this. I’ve seen carbon fiber barrels start stringing in 4 to 5 shots, and I’ve seen it in 11 to 12 shots. While this may not affect the average predator hunter, it is still a consideration as it’s a direct effect on performance.
Steel has a higher expansion rate than carbon fiber at it heats up. Carbon fiber used in the construction of barrels has a negative thermal expansion coefficient. Meaning that it shrinks as it is heated. But, this only occurs in the direction parallel to the fibers. There is a slight amount of growth in the perpendicular direction, but nothing significant enough to note. This, combined with the smaller diameter barrel core, can contribute to why a barrel walks as it heats up.
One last bit on carbon fiber barrels and thermal conductivity. AKA, heat dissipation. As already discussed, it takes heat longer to dissipate out from the steel barrel core. This can result in overheating of the barrel core in the area of the throat. If this occurs, the higher average heat temps and higher average peak heat duration can result in quicker and greater throat erosion and fire cracking of the bore. This is something that the average predator hunter may not be concerned with, but it could be of concern to someone who hunts hogs and gets into big groups.
Is BRDGW Moving Away From Carbon Fiber?
Yes and no. I’ve dropped a bit of information here to hopefully provide some useful information about carbon fiber components, as well as some advantages and disadvantages.
In a decision that wasn’t easily made, BRD is moving away from carbon fiber handguards and for the near future, carbon fiber barrels on BRD rifles. The ultra-lite handguards used on our Pro rifles will be replacing the carbon fiber rails. As discussed in the handguard section, these handguards weigh less than the Lancer carbon fiber handguards, while being more rigid and smaller in diameter for better handling characteristics. If a client wants to customize a rifle with carbon fiber components, this will be an option with understanding the pitfalls of the lead times for those components.
Due to extensive lead times on carbon fiber barrels from my preferred carbon fiber barrel manufacturer, I’m looking into different options. Carbon 6 has been the carbon barrel company that’s been used exclusively at BRD Gun Works LLC. Once I’m out of the carbon fiber barrels left in stock that will be the end for now. I’ve shot a lot of different carbon fiber barrels from various manufacturers, and I’ve not found a carbon fiber barrel that shot to my expectations or has been as consistent as a Carbon 6. Not even Proof. Unfortunately, their lead times over the last year have become delayed and significant. This has put me in a position to miss promised lead times to many clients. By a significant amount. Some are still waiting on their rifle(s). As it is, I was ordering batches of barrels in advance so that I could keep a steady flow of barrels available. Now, I need to order carbon fiber barrels a year or more in advance. Being more of a custom shop for the AR platform, this isn’t conducive to business. While some cartridges are a staple in the predator hunting community, there is still an ebb and flow of what individuals want. Whether that be barrel length, profile, chambering, or something else.
While I assess and test other carbon fiber barrel options, our Pro barrels will be fluted in the Invictus series large frame AR’s and replace the carbon fiber barrels. The C6 carbon fiber barrels that I used in BRD rifles were a heavier profile with a .875” gas block journal. While a C6 20” 243 Win carbon fiber barrel weighs just under 3lbs in this configuration, in my opinion it is one of the reasons they shoot so well and is worth giving up a little weight savings.
I’ve been running one of the Nyx fluted barrels in my personal 22CM. The Nyx barrels are a custom BRD profile, and for the large frame AR’s they’re a large profile that are fluted with flutes specifically laid out for depth and width to reduce weight without having a negative impact on barrel performance. As stated earlier, these barrels are more rigid than a C6 carbon fiber barrel and weigh just a bit more than a C6 barrel of the heavier profile.
At the time of this writing a new model has been recently released in both the Vertex and Invictus series of rifles to reflect the change. It is the Nyx. The Nyx is what is replacing the Carbon and Elite models.
Invictus Nyx Side Charge 243 Win
Vertex Nyx Side Charge 22 ARC
