How Well Do Melonite and Nickel Boron (FailZero) Resist Corrosion?

Because I was sent a few different handguards by Rainier Arms recently, I needed to disassemble and reassemble a few upper receiver assemblies. One of those was the 5.45×39 upper sent to me by Spike’s Tactical last year. It’s seen crate after crate of corrosive surplus ammunition, and has never been properly cleaned.

Coincidentally, I had just received a CAT M4 bolt scraper tool from Rainier, and thought I’d see how much carbon it would remove – there will be a separate post on that.

But the topic of this post is corrosion. Do you think that, after all the carbon was scrubbed and scraped away, I found corrosion on the nickel boron parts? What about the barrel, front sight base, and gas tube, all of which were Melonited? Here’s a current photo of the barrel and bolt carrier group. I’ll post more photos on October 5th.

Let me know what you think in the comments below.

spike's tactical melonite barrel and nickel boron bolt carrier group

7 thoughts on “How Well Do Melonite and Nickel Boron (FailZero) Resist Corrosion?”

  1. My guess is the corrosion level would be about the same as a standard “run-o-the-mill” BCG. I’d love to believe the claims that FailZero thows out there, but I’m skeptical. Maybe because of all the “gimmicky” stuff on the market today…I dunno.

    Interested to see the actual results.

  2. I am building an ar15 and, all the parts are from Wilson Combat. The bolt carrier is Wilson Combat NP3 coated. The receivers are factory anodized and I want to get them coated before I build it. While the best results would be NP3 coating everything, I want to get the receivers Cerakote. Will the Cerakote and NP3 combination mess up each other or is it ok? Will I get NP3 dust in my lungs from the Cerakote rubbing against the NP3?

      1. The finish on the receivers is not that great, it does not have the Teflon coating that Wilson normally uses, just a cheap anodizing. I want to get the receivers and stainless steel barrel coated with something. The bolt carrier is already NP3 coated. Should I send it in for Robar NP3 or try the Cerakote, or something else?

        1. Who made the receivers? As long as the upper receiver has dry film lube inside (looks like dried milk under certain light), it should be fine.

          Do you want the interior of the bore protected, or just the outside a different color?

  3. I’ve been wondering myself if these are just marketing hype or do they actually help. Looking forward for the results.

  4. I have about 3500 rounds through my Spikes 5.45, and I generally do a 5 minute bolt and carrier wipe down between sessions. No corrosion that I can see so far, but we will see how it fairs during the rainy season.

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