GunLink Visits the Home of Black Nitride, AR Components

Checking Out the Operations at H&M and Rubber City Armory

If you have been keeping up with our weekly posts about what’s new at Brownells, you may remember a recent one in which Paul Levy told us about the low mass AR-15 bolt carrier group from Rubber City Armory (RCA).  This caught my attention since Rubber City is the nickname of a certain Ohio city from whence one of the GunLink team members originally came and it just so happens that we get back there to visit every so often.

I reached out to RCA and who else is on the other end than Chris Cerino himself – 2nd place finisher on History Channel’s Top Shot Season 1 and Top Shot All Stars, Gun Talk TV field host, and firearms instructor.  Add to that list Director of Operations for Rubber City Armory, a subsidiary of H&M Metal Processing – the home of Black Nitride™.  After exchanging a few communiques, we arranged to stop by and check out their operation on an upcoming trip to the area.

The GunLink team arrived on the day of our visit and, wouldn’t you know it, Chris had bailed.  Can you believe the nerve of this guy?  Only kidding – Chris was attending to the higher priority of kicking ass and taking names at the Blue Ridge Mountain 3-Gun Championship.  Despite the lack of television personalities accompanying us, our awesome hosts Shade and Pete gave us the grand tour and showed us around both the H&M and RCA sides of the equation.   

The Black Nitride Treatment Process

First up was the tour of H&M’s metal finishing operations.  H&M has been performing various metal treatment services since the mid-1940’s, when it was founded by namesakes Ernie Hedler and Art Marble.  Today, those treatments include heat treatment, black oxide finishing, and Ferritic Nitrocarburizing – a mouthful of a way to say the process that generally goes by a handful of trade names that most of us have probably heard in various firearm circles.  Here, it goes by Black Nitride and they’ve pretty much got the process nailed down.

H&M has provided metal processing services for various industrial and commercial applications such as the locomotive, auto racing, and aerospace fields.  We are, of course, more interested in the firearm side of things and, at H&M, that’s a big side!

QPQ_ASTM_B117Tucked in behind their comprehensive metallurgical lab, laser engraving bay, salt spray corrosion testing area, and various other collections of really cool toys was the heart of the operation:  the QPQ line.  Here, metal pieces to be treated are subjected to the salt bath ferritic nitrocarburizing process (quenched), polished, and quenched again.

We got to see parts along each step of the treatment process, from the initial nitriding that leaves the parts with a matte finish of iron nitride on the surface, the polished pieces with a glossier dark finish, and the finished pieces with a thin magnetite layer.  These finished pieces have a deeper black appearance and include all of the QPQ benefits including increased wear resistance, lubricity, and corrosion resistance.

result5With roots in treating metal parts for the diesel locomotive and aerospace industries, in recent years, the balance of H&M’s nitriding work seems to be tilting toward the firearms industry.  Although their client list is played close to the vest, taking a look at the examples of the work on their website and social media makes it pretty easy to pick out some major players.  Aside from nitriding parts for RCA, they do a lot of work for a number of firearm manufacturers.

RubberCity_5229After the parts are treated and cleaned, and after any extra work requested by the client (such as laser engraving or additional testing), each piece is individually packed and made ready to head out the door.  We can’t tell you who, but we saw components for some high-demand firearms getting ready to ship that will make a lot of people happy.

Despite being the bulk of their work, huge OEM contracts aren’t all they do.  H&M also handles piece work for firearm refinishing, which is great news for anyone rehabbing a gun who wants protection beyond what a cosmetic blueing process or surface covering like cerakote offers.  Hmmm, do we smell a possible next step for our KelTec P11 Improvement project?

To learn more about H&M and their metal treatment services, check out

Rubber City Armoryrubber-city-armory-logo

Not far away from the metal processing facilities, in a nondescript building, was the Rubber City Armory headquarters.  This is where the magic happens that originally got our attention, but we found out that there is much more to RCA than just the low mass BCG that Paul Levy told us about in the video – even beyond the handful of RCA products that Brownell’s carries.

RubberCity_5279In the video, Paul focused on the low mass AR-15 bolt carrier group.  Especially popular with competition shooters for 3-gun matches and the like, particularly when combined with an adjustable gas system, the low-mass moving components can result in an incredibly soft shooting rifle that makes follow up shots faster and easier.  Although Paul mentioned an adjustable gas block, RCA also manufacturers an alternative means of regulating the gas coming into the carrier:  the adjustable gas key.  The key features an adjustment screw that regulates the amount of gas that makes its way from the tube into the carrier and a set screw to keep the adjustment from moving around.

RubberCity_5274The low mass carrier has multiple slots cut out along its length, as well as some extra fat carved out from various places on it, mainly around the forward portion of the carrier.  Part of the weight loss regimen to get the BCG down to only 8.9oz also includes trimming down the lug on the bottom of the carrier from full-auto specs to semi-auto specs – bad news for anyone dreaming of using this carrier in their M16.

RubberCity_5271But fear not, full-auto enthusiasts, RCA offers a full-fat version with their M16-profile carrier with the same nitride coating as its little brother.  For those looking for the best of both worlds (and those with an ample gun-stuff budget), RCA has just the thing:  their new, absurdly-lightweight Black TI titanium bolt carrier group.  Tipping the scales at a mere 7.8 ounces with a full M16 profile and having a “propietary aerospace nitride coating”, it felt like a toy when Pete first handed it to us.

Standard, low-mass, and titanium carriers for 5.56 AR rifles aren’t the entirety of the RCA lineup, either.  They create a full line of carrier components for a variety of calibers including .308, 7.62×39, .458 SOCOM, and 6.8 SPC as well as other odds and ends like their tunable 5.56 muzzle brake.  Throughout the entire lineup, RCA adheres to the “Nitride All The Things” ethos, treating pretty much everything from the bolt, carrier, and key down to the cam pin and firing pin to make the entire assembly durable, corrosion resistant, smooth running, and easy to clean.

RubberCity_assemblyIn the production area, Pete walked us through the process of assembling, staking, checking, and packing RCA’s aftermarket bolt carriers.  No robots here; each step is completed by real, live American workers right there in their Ohio-based facility.

In what is probably the gun guy’s version of seeing your own Corvette being built (albeit, perhaps on a smaller scale), we got to take with us the low-mass and standard M16 RCA bolt carriers that Pete built before our very eyes.  We plan on putting them through the paces in the Team GunLink AR stable to see how the Black Nitride parts perform and hold up compared to the phosphated ones that we normally use, so keep your eyes open for a follow-up post right here on the GunLink Blog.  We suspect that it will be a good experience, given the caliber of rifle experts who put their “stamp of approval” on RCA products.

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