The Problem With Nickel-Boron

A few months ago I discussed metals and coatings for firearm actions. I noted the NiB (nickel-boron) gets discolored by fouling, but my photos only showed a sparkling new NiB-X BCG. Following is a picture of what it looks like after a few hundred rounds of use, followed by ultrasonic cleaning and then aggressive scrubbing with steel and brass wire brushes. For comparison I show my heavily-used chromed BCG on top.

AR-15 bolts: Chrome and NiB-X, as clean as they get

Is this just a cosmetic issue? This is the only cleaning I’ve given the NiB BCG. I haven’t lubed it and I have subsequently run a few hundred rounds more without any action failures. However it seems plausible that if fouling can bind to the surface this stubbornly it could build up to the point of overtaking the nickel-boron’s lubricity and causing a stoppage that only traditional lubricants prevent. As noted in the original article this is not a problem with chrome and NP3: All photos of those to date have been after they were used and wiped clean with minimal brushing.

Update: A number of people say it’s unfair to compare a BCG from a piston gun to one from a DI gun, since the latter is subject to much harsher fouling. So for comparison I pulled and cleaned an NP3-coated BCG I’ve been running in a DI gun: pictures in my comment below.

15 thoughts on “The Problem With Nickel-Boron

  1. flaguy

    I haven’t experienced any stoppage with my NiB after shooting a few hundred rounds between cleaning, nor have I read about one.

    I understand its not necessarily the BEST coating available, however I haven’t seen any proof that the build up has caused a stoppage. Best test would probably be to shoot a suppressed SBR with a couple thousand rounds and see if it stops.

  2. federalist

    Stuck NiB actions are a rare occurrence, but you can find a decent number of reports of them online.

    I haven’t experienced or directly observed one. I merely note that they have been reported, and that based on what I see running my BCG and what I have gathered of the microscopic structure of the coating it seems plausible that the BCG could jam up in this fashion.

    I would also note that since NP3-plated BCGs are available for the same price I see no reason anyone should buy them NiB-plated.

  3. Bart Noir

    The top BCG is from a Ruger piston gun. This is comparing apples and oranges.
    In my case I oil my Fail Zero NiB BCG same as if it were a parkerized GI group. And I notice that carbon is building up on the boat tail, same as on a GI group. No biggee, dirty and wet works, just don’t let yourself shoot with a dry BCG.

  4. federalist

    Sort of true, except that I almost always shoot suppressed and pistons don’t seem to help fouling much there. If you want to see how a chromed DI BCG cleans up here’s one example. I’m shooting NP3 BCGs on my DI guns now and might do a future post on those for comparison.

    Note that NiB is billed as self-lubricious, and also that lubes don’t stick to it as well as coatings that are designed for lube.

  5. Corey

    Discoloration isn’t only associated with an external buildup of some kind. I.e. case hardened SA revolver frames have discoloration, it doesn’t mean they’re coated with anything (other than varied thicknesses of surface oxides). If you aren’t getting anything more off a NiB BCG with solvent, then chances are there isn’t anything really there to get off. And if there is, well then clean it some more…

    No one ever said you could run a NiB BCG without lubrication forever without cleaning it and never have a failure. Nor can you run a chrome BCG, with lubrication, forever without failure without ever cleaning it.

    Chrome cleans up and looks nice after use, but requires lube, NiB doesn’t look as nice after use and after clean up, but doesn’t require lube. This article didn’t really resolve anything or even raise a relevant point… Any BCG requires periodic cleaning, no one said it didn’t require cleaning. So unless you’ve determined and proven whether there is actually a buildup of some kind on the NiB AFTER cleaning it, you’ve just wasted 5 minutes of my time that I’ll never get back.

  6. federalist

    To offer a more fair comparison I took an NP3-coated BCG out of my DI 300BLK gun, which has a pistol-length gas tube and which I run exclusively with a suppressor. I have never cleaned this one, and it has fired hundreds of rounds with no lubrication. Here are pictures straight out of the gun, then after wiping everything with a shop rag and nylon brush, and then after cleaning with KG1 Carbon Remover. (If I was detail cleaning I would probably make another pass with a solvent and bronze brush if necessary, but this is going right back to work!)

  7. Gabriel

    Are there any issues with Nickel-Boron coating or just Boron coating parts in an ultrasonic cleaner? Does it affect the finishing?

  8. federalist

    This article talked about professionally NiB-coated parts. I’ve heard in passing about trying to impregnate surfaces with hexagonal Boron Nitride powder using ultrasonic cleaners. If you can provide any more info on the latter I’d be interested!

  9. Sam

    I have an LWRCi M6A2 10.5″ suppressed SBR with a NIB BCG. The only time I had any issues with the SBR was when I installed a JP Rifles Captured Buffer Spring. Once I adjusted the damping mass and the swap out to a spring with a heavier spring constant. Once I did that, I had no problems with it. Sure, is not as slippery as it was when it was brand new, but some Hoppes #9 lubricant and it works like a charm.

  10. federalist

    Hoppes #9 is a cleaner, not a lubricant. And the whole point of NiB is that it’s supposed to not require lubricant, as it is “self-lubricious.” And part of the problem is that it sheds conventional liquid lubricants.

  11. Jason Meador

    That is normal discoloration for NIB-X . Its actually a sign that you have a NIB-X instead of the less effective NIB
    and other lesser Nickel Boron Coating. If your new NIB-X Carrier comes in and stays bright as chrome I would be asking questions about whether you actually have the real NIB-X coating.


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