Diamond Like Carbon The DLC Solution

The NRA show in Indiana this year was a real joy for me. We had the luxury of sitting with several of the companies we have been working with for a long time and finally meet some of the newer ones. In addition to trolling through the booths we would randomly run into other interesting people. Eric Tinnerman the president of Perf Arms was one of these people.

While speaking to another bolt manufacturer about the virtues of a bolt they had been making, I was introduced to Eric. Perf Arms is a newcomer in the firearms market and fashions themselves after the BASF motto. We don’t make the things you buy; we make the things you buy better. Eric and his company, in an almost accidental way, are changing the firearms industry. Let me tell you that story.

After years in the firearms industry I have learned one very important truth. The AR-15 and 1911 are iconic weapons and the need to regularly clean and lube parts to ensure reliability is something many companies have tried to change.

The AR-15/M16/M4 platforms direct impingement gas systems are dirty and they transfer heat and dirt to the bolt carrier group. While cleaning them is going to be required no matter what you do, people have tried to solve the need to oil guns. Oil while it solves some problems, is a magnet for dirt and carbon and can increase the chance of debris causing malfunctions.

For many, claims of a lube less rifle are a solution to a non-existent problem. However in environments like Iraq, Afghanistan and other desert-based climates sand and grit have put the weapons system to the test. Running the weapon wet makes it a magnet for dust and debris. Running it on the dry side makes the weapon prone to carbon fouling and failures.

There is no shortage of coatings on the market to “improve” your weapon system. They range from decorative solutions to practical coatings that harden the materials, increase the lubricity or a mix of the 2.

My intent here is not to hold science class, but when discussing coatings we need to know a few things.

Coefficient Of Friction (COF): In the simplest of terms is a measurement indicating the amount of friction between 2 surfaces. It is rated from near 0 to greater than 1.

Nickel Boron or NiB-X can offer a lubricated COF of .07 and this is what is considered a high lubricity or low fraction value in the weapons market.

Like so many other great ideas Perf Arms and its leading edge coating DLC (Diamond Like Carbon) being used on weapon parts started as a way to win an argument.

True entrepreneurs, the guys who thrive on building companies and all that goes with them are a rare and interesting breed. I have had the pleasure of working with several and every one of them I know has both made and lost millions. The money is a side effect of the personality these men and women wield, not the other way around. These are the types of people who will spend $100 to win a $1 bet.

Here is how the conversation developed into what is likely to become one of the most important coating innovations available to the consumer and military firearms markets.

Partner1: You need to get you a couple AK’s

Eric: I can’t do it; you know the Army in me just won’t let me.  I’m comfortable with my AR.  It’s like an old friend.

And then the inevitable…

Partner: Yeah but the AK ALWAYS works.

Eric: yeah, but I can hit things with my AR.  (I know AKs are accurate and all this isn’t a desire to reopen that conversation, but they just aren’t accurate in my hands it seems).

Eric in an effort to save face had to find a way to reduce the COF of the AR-15 platform to allow for it to function in the same types of horrible environments the AK’s have become famous for. No small task and further he would not be the first to try this. Though he may be one of the first to actually succeed!

It is important to mention that Eric had an unfair advantage over most people. Besides being a serial entrepreneur he owns a company that is heavily invested in cutting edge technologies including millions of dollars put into scientists, engineers and machinery to coat commercial drill bits in a product called DLC or Diamond Like Carbon.

Diamonds are one of the hardest materials available and are often used for drilling and cutting due to their hardness.  Most people know this already but what many may not be aware is that they also have a very low COF.

DLC offers a COF dry of .04. This is a significant reduction over Nitride, Phosphorus and NiB-X the most commonly used upgraded coatings on the market.

Eric describes it in highly technical terms that some of you may appreciate.

“This is a Plasma Assisted Chemical Vapor Deposition that basically creates amorphous carbon molecules that display some of the typical properties of diamonds, IE hardness, coefficients of friction etc.  With average coefficients of friction that are .04 (DRY) I believed a bolt coated with this material would not only run dry but given the wetting properties of DLC would not attract or collect dust, dirt, or carbon.”


Like Pythagoras exclaiming “Eureka” after developing the 47th problem of Euclid Eric had discovered a way to both harden a standard BCG and make it run with a lower level of friction then an oiled weapon would. All while creating no home for dirt and carbon to foul the moving parts.

Unfortunately while the idea was sound anyone who has started a new business knows things are never easy. Eric now needed to produce a bolt to show his partner that would meet his list of requirements.

Because DLC was applied in vacuum chambers and able to evenly coat a material it was absolutely necessary that the BCG’s he worked n be in a raw state. This would ensure that no hills and valleys would develop as is sometimes seen in the coating industry with products like chrome.

Unfortunately there is only a few companies that can produce reliable properly spec’d raw BCG’s and they require large minimum purchases. The only advantage was that when your goal is to keep inside existing Mil-Spec tolerances your going to need several tries to get a coating like DLC to the exact measurements you want.

Eric goes on to describe what happens next:

 Next came the fun part.  There are always tolerances in anything built.  Your ability to hold tolerances depends on equipment.  Having said that the coatings we are dealing with are in Micron thickness we are talking about 0.000039 of an inch.  This coating had to be custom for each part of the BCG’s, extractor, bolt, pins, gas key, etc.  Over the next 6 months we found multiple ways to not coat a BCG with DLC.  Because even though we took measurements we still had to tweak the coating thicknesses until we finally found one that worked.

After millions invested in the primary R&D for DLC in their initial market and now tens of thousands into research for the firearms industry the first fully functional and ready to go Perf Arms bolt carrier that met the strict requirements for tolerances and function was produced. This one bolt carrier may be the most expensive bolt carrier ever designed.

 I went out that very night to the local range armed with a pile of Pmags, a brand new DPMS oracle, 1000 rounds of Tula steel case and my new baby, the BCG coated with DLC.  Yeah I’m gluten for punishment.  In my mind the bolt being able to run with clean ammo wasn’t good enough…no this need to run with the nastiest stuff I could find at the time (sorry Tula, love your stuff but lets face it…its dirty).  My partner and I went about defiling this poor AR.  Mag dump after mag dump, taking turns running the rifle and loading mags, while recording with our phones in between.  All the while talking about how amazing it was, the gun was dryer then the Mohabi desert I had done so many NTC rotations at while in the army.  In what seemed like forever for our trigger finger and was really les then an hour, in that time we had gone through 1000 rounds of Tula without any jams, without having to lubricate and without cleaning.

So how did the BCG hold up after 1K rounds of some of the nastiest ammo around fired in rapid succession?

 The rifle was so hot at this point I couldn’t even get to the bolt to see how it had handled it!  The waiting for it to cool was killing me and I knew it was going to take too long.  When the hand guards melt off the gun and the gas block comes loose and the barrel turns a weird green gray shade and you get a pinhole in the gas tube you know your AR is a little hot.  But I had to get the rifle tore down.  So off to the back of the shop I went and in the toilet the rifle went (call me the dumbest smart guy you ever met) I was determined to check this bolt. 

 To my surprise the bolt wasn’t even hot, but within minutes of handling the bolt I was covered in carbon, which makes sense since carbon has to go somewhere if it’s not stuck to the bolt it’s going to end up on your hands.  If you want to know what I saw check out our website we prominently display pictures of the bolt from that night.

The above images are after 2800 rounds of Tula without CLP cleaning. They represent what a wipe down of the carbon using a rag will produce. 

We here at GAT had been lucky enough to get our hands on one of the early production runs.  We let one of our writers take the gun to the Haley Strategic carbine course a few weeks back and run the bolt in 2 different guns. Over the 3 days of the class about 1200 rounds of ammunition was sent down range using this BCG. No cleaning was done at the range or between classes. At the end of the 3 days the result was one gnarly and dirty BCG.

Once I removed the BCG there were several things that took my attention.

  • Carbon build up wiped right off for the most part. So much so that while I normally do not wear gloves when cleaning a gun I had to with the carrier because my hands had turned black so quickly
  • The carbon that did not just wipe off came off very easily with a bit of CLP.
  • There was not the usual amount of wear that I see when testing a new BCG and especially not the wear I would expect from running a gun dry.

Since that class I have been running the Perf Arms bolt exclusively in my primary weapon. Each time cleaning it is a dream. I do find that the actual blot (not the carrier) still needs to be scrubbed to remove carbon fouling but overall the cleaning process is very simple.

The finish on the carrier is exquisite in its coverage and color. A deep shiny black that is a real pleasure to look at. While looks should never be a deciding factor it is a nice extra touch.

We have about 3K rounds through our DLC coated Bolt Carrier Group, a combination of Detroit Bullet works and steel cased Tula rounds. We have not had a single hiccup in running the weapon. In addition to our testing Perf Arms has been running a bolt completely dry since day one with many more thousands of rounds than we have pout down range without failure.

DLC is likely going to be the next major coating we will see flood the market, replacing NiB-X and some of the other new coatings that do not offer the same level of advantages. We discuss what it can do for bolt carriers here but that is only the tip of the iceberg. I am aware of several major players right now working with Perf Arms to bring some incredible solutions to the handgun market as well as further application in the AR-15 arena.

I’m going to leave you with one last conversation between Eric and his business partner:

Partner: You need to get you a couple AK’s

Me: I can’t do it; you know the Army in me just won’t let me.  I’m comfortable with my AR.  It’s like an old friend.

And then the inevitable…

Partner: Yeah but the AK ALWAYS works.

Me: yeah, so does my AR!

If you are interested in picking up a BCG, Bolt or just the Bolt Carrier coated in DLC check out the pricing below:

  • DLC Bolt Carrier Group for $230 on sale now for $175
  • DLC Bolt for 84.99
  • DLC Bolt Carrier $129


Charles is the editor for 248 Shooter a midwest based gun news and gear review site as well as Online Content Director for On Target Magazine. He is an avid student taking classes from top tier trainers around the country. Charles shares his love for training as well as experience and opinions on some of the most talked about gear and products used by competitive shooters, military, leo and civilians.