M&P 40 Nickel Boron Coating

[x260Truesnipes]

I just purchased an M&P 40 full size with the nickel boron coating from my local gun shop. I took it home and put a fresh coat of oil on it and let it sit for about 24 hours. After letting it sit, I carried it for about 4 hours and when i went to put it away for the night, I noticed small brown spots forming on the left and top of the slide. Is this a manufacturer defect or is it something nickel boron does? I have never owned a gun with this coating, so I am new to the care of it. I have heard that the coating is extremely tough and almost impervious to rust.

 

[Tinhack]

Who did the plating? Sounds like poor preparation during the plating process or the original finish wasn't removed entirely (down to bare metal). If it's from the "local gun shop", take it back. I can't see your pistol from here but brown spots might indicate corrosion under the nickel plating. If this is the case, the plating is porous and the corrosion will always come back. In time, the plating will start peeling.

See if the spots polish out then clean and leave it over night again without oil. See if the spots return.

 

[Tinhack]

I forgot to mention that Nickel-Boron Nitride plating is normally used on friction or wear surfaces. It's a nickel plating process with the inclusion of boron nitride nano-particles held in suspension by agitation in the plating electrolyte. As the plating takes place, the particles are locked within the nickel to hold them in place.

Boron nitride/nickel is an extremely slick, abrasion resistant, low-friction, high lubricity coating. About the only thing "slicker" is Tungsten Disulfide. It's about 10 times slicker than Teflon.