A Guide to Carbon Fiber Handrails

Written by Jack Billington

Introduction

As with most materials that seem to be advanced, they all started out either in the military or the medical field, which are the two main sectors that invest heavily in research and development. Carbon fiber has been around since the 1970’s and was first used in naval and air applications, and was then adopted by the hyper-car automotive industry.

Carbon fiber is now found in many applications, including ultra-light bicycles, tennis racquets, and various optical applications. Only recently has this amazing material been included as a raw-material for weapon parts.

A Guide to Carbon Fiber Handrails

Carbon Fiber is made up of aligned carbon crystals, and are honeycomb in shape. The shape is based on the molecular structure of the carbon atom, which is 6 in the periodic table. This means that there are six electrons around a nucleus and as such, the molecule takes on a distinctive six-sided shape. Carbon fiber strands are then woven into carbon cloth, plate carriers, etc, and in many cases woven together with another material such as Kevlar, glass, and aluminum, all prepared for specific applications. You will rarely find pure carbon fiber as an end product.

Characteristics

Carbon fiber has some unique properties that make it so desirable, yet, as with any unique material it also comes with a few issues. To start off, carbon fiber has a thermal expansion rate that is one third that of aluminum and a half of steel. This is a great property and is why it can be used in handrails since it will not change its structure or shape as fast as alternative materials. This is also its weakness since it does not have such a coefficient of expansion, machining considerations have to take into account the expansion of the materials that it comes in contact with, and also consider the effects of composite materials too.

Another great property is its thermal conductivity, which is extremely low and is ten times slower than aluminum. This means that you can hold a piece of carbon fiber that is extremely hot on one end and not feel the heat at the other end, unlike aluminum that transfers heat with quantum efficiency. This particular characteristic makes carbon fiber a particular favorite for handguards since it retains a cool touch even when all the parts around it are nearly red hot.

Carbon fiber is exceptionally light, so it beats hands down steel the heaviest alternative, wood, and aluminum both are heavier than carbon fiber. Being so lightweight is one of its biggest advantages, and this is combined with its exceptional strength. The tensile strength and lightness of this material are what made it so attractive in the first place, before all the other characteristics.

On the other hand, its smoothness and rigidity misdirect you from the downside of its capabilities, which is edge fraying, machining costs and material cost. Carbon fibers will fray at the edges after time, and to counter this issue, most fabricators will tip or cover the edges of a tube with aluminum, titanium or another metal. The machining process can be very hard on the inexperienced since carbon fiber is very hard and only special toll tips can cut through it efficiently; most standard tools will wear immediately. The other cost is the actual raw material that is significantly higher than all three alternatives; steel, aluminum, and wood.

The final characteristic that needs to be mentioned is the nature of this material, it is a fiber, and as such is directional, this means that forces travel along its length, along with the fibers. Recoil impulses will be resisted by the material, but it will jolt you when these forces reach the end of the tube. Most manufacturers add a neoprene wrap to counter this issue, so when buying any carbon fiber part that is handling loads, check to see how the load is managed when it reaches the end of the material and hits the next part.

To sum up carbon fiber characteristics; This is an expensive material, that has an expensive fabrication process but is lighter, more heat resistant and more durable than its counterparts, and is an efficient and perfect material for handrails, beating any other material hands down.

Just to get an impression of one of the properties of this material in relation to other materials, carbon fiber strength measured kN.m/kg

  1. Kevlar: 2514
  2. Carbon Fiber: 2457
  3. Glass Fiber: 1307
  4. Steel alloy: 254
  5. Aluminum alloy: 222
  6. Polypropylene: 89
  7. Oak: 87

As you can observe, in strength alone, carbon fiber outperforms steel, aluminum, plastics, and wood. It outperforms steel by 10x, which gives that amazing weight to strength ratio.

Another characteristic is heat transfer, which is measured in W/(m.K)

  1. Aluminum: 250
  2. Carbon Steel: 54
  3. Carbon Fiber Reinforced Epoxy: 24
  4. Pine: .12

In the case of heat transfer, carbon fiber as epoxy and not as carbon fiber alone (which you don’t get) provides 50% of the thermal insulation properties of steel and is 10x better than aluminum. This means that it will take carbon fiber twice as much heat over twice the time to heat up as steel, and 10x the heat for 10x the time as aluminum. Do the math yourself. Even after shooting session, you can easily put it into your sniper bag.

Review of carbon fiber handrails

For those that don’t recognize a carbon fiber handrail, it is that dark grey thin sleeve that fits over a barrel. It is so light and thin that at first, you think it might be part of the barrel providing a cooling solution. That is not the case; the material is so efficient that only a thin sleeve of this product will provide the same comfort and ease of use that a bulky plastic or wood version provides, and it does so at a fraction of the weight with a much better finesse.

Carbon fiber handrails are the Ferrari’s and Lamborghini’s of the gun world.

A brief history of this material in the gun world will explain why lightweight guns were not popular until recently. Winchester introduced the Model 59 semi-automatic shotgun way back in the 1960’s. This gun’s barrel was wrapped in fiberglass and weighed only 6lbs. You might have thought this an advantage, but most people were so used to heave weapons, that most if not all of them could not target and shoot this gun with accuracy. In 1865, Winchester discontinued the Model 59 line.

Today, there are a handful of companies that manufacture carbon fiber sleeving and what they claim are these advantages which I will review individually:

  1. Extreme weight reduction.

Yes, this claim is correct, since carbon fiber is a third of the weight of the same mass of steel.

  1. Less warping and vibration than an all steel barrel

Yes, carbon fiber will reduce warping and vibration.

  1. Optimized cooling is leading to longer barrel life.

There is no argument that this material handles heat better than steel. However, there is no proof to the claim that barrel life is improved.

  1. Improved accuracy.

No, this material has nothing to do with accuracy, that is in the hands of the shooter. The material might make it easier to hold a weapon, and maintain a grip during heavy fire conditions, but accuracy, not a handrail function.

  1. Stronger and Lighter than steel

Yes, already shown in the table above, carbon fiber is 10x stronger than steel.

  1. Corrosion resistant (rust, oxidization)

Yes, carbon fiber is extremely chemically stable, however, consider what the material is meshed together with, that other material could be susceptible to corrosion.

To sum up this section, the claims that some manufacturers make are unfounded. What I have noticed is that when new material comes along, everyone starts to make suppositions based on unsubstantiated premises. In many cases, a lot of copywriters take technological and scientific data and write it up incorrectly, making wild claims that are totally incorrect. On the other hand, when focusing on carbon fiber, this material is lighter, handles heat better, and is stronger than steel.

Carbon Handrail Types

There are a variety of carbon handrails on the market; all the manufacturers claim that they produce the lightest handguards on the market. So, let’s just take a quick look at some of the products on offer.

The metrics used to evaluate each one does not include price, I am comparing product characteristics based on material weight, dimensions, and design (which is subjective).

All products are rifle length, so they are around 12” long, and I am not reviewing the barrel nuts. I include two non-carbon fiber handrails for reference, check out the weight to length ratio.

Brand Material Length (in) Weight (oz) Ratio oz/in
Magpul 12” Rifle Rail Polymer 12.6 12.1 .96/1
Daniel Defense DDM4 Aluminum 6061 12.4 14.1 1.13/1
Lancer Lightweight Carbon Fiber 13 8.6 .85/1
Faxon Carbon Fiber 15 6.71 .53/1
Bravo Company BCM Carbon Fiber 13 7.8 .78/1
Brigand Arms Carbon Fiber 12.4 2.9 .35/1

As you can see in the images that I placed in this article, designs using carbon fiber are radical, and the Brigand arms mesh is perhaps the most radical in style and performance. It is also the most unique, since it is a 100% carbon fiber product, and I have to present the fact that I did mention this is not a probability, well here is a contradiction to this statement made earlier. The Brigand Arms handguard is made of a lattice weaved carbon fiber base, this means that they weave the carbon fibers in opposite directions, and that creates an ultra-strong and ultra-lightweight solution.

Conclusions

Price is an issue, and carbon fiber handguards are the best you can get, but the costliest. If you want to look cool, feel cool and have a lightweight experience, then there is no arguing with a carbon fiber handguard accessory. If you are willing to pay the price, you will never be upset with the decision to go carbon fiber.