DLC BCG???

[Harlequin1138]

Diamond like coating on a new BCG. Has anyone seen one or tried one or know if it's a good thing or just a new gimmick?

[300Blk]

Well....

It is a hard surface, which is good. But it may not offer much corrosion resistance unless it is over nickel plating. I would be suspicious of anyone NOT doing nickel plating. I would also be suspicious of anyone who IS doing nickel plating.

AAC bolt carriers are machined undersized to account for the thickness of the nickel plating. This is expensive to do, because we cannot buy off-the-shelf carriers in bulk.

Probably nearly anyone who did the nickel plating does not do this. To keep their part in spec, they would use too thin a layer for good corrosion resistance, or maybe they use a thicker layer and they end up over-sized. Not a problem for them, as they just replace them for anyone who complains, which is going to be very few people who notice because few people shoot a lot, and that is much less expensive than doing it right.

So my opinion is that I would stick with mil-spec unless you are sure they are making a great effort to go beyond mil-spec correctly, as with AAC.

[Mgoirea]

From my limited undergraduate chemistry background, I would be worried about the coating burning off.

[rpk47]

I am looking at a Ni-B BCG. It's very corrosion resistant because it's mostly nickel, has great wear resistance, it reduces friction between parts well, and is a common coating to find these days on BCG. All this makes it likely that you can find a quality BCG that is in spec and you have a coating that will out live several barrels in your AR.

You can even get it in multiple colors now if silver isn't your thing. However, I dont know how they are achieving those colors and if it affects the Ni-B in any way so I will be sticking with the polished ones.

[mrgein]

NiB is an awesome coating, im sure something else will come out that potentially "beats" it but i wouldn't buy a NiB from just anyone, mine was done by AAC in a complete upper. I hear the teflon NiB is a little superior to just regular NiB but im not a chemist in any type of meaning.

[rpk47]

NiB is an awesome coating, im sure something else will come out that potentially "beats" it but i wouldn't buy a NiB from just anyone, mine was done by AAC in a complete upper. I hear the teflon NiB is a little superior to just regular NiB but im not a chemist in any type of meaning.

Nickel Teflon and Nickel Boron are simmilar in that they gain wear resistance and corrosion resistance by using nickel but they achieve the friction reducing properties differently.

NiB when plated to a metal builds up in tightly packed columns with a dome top, like in this picture.


That surface acts sort of like billions of tiny ball bearings, the surface area that is touching and sliding is greatly reduced. Also because they have a much larger surface area that aids in dissipating heat. Thats why this coating is used in things like saw blades to increase the life of the blade.

Nickle Teflon on the other hand uses the properties of teflon, or more precisely the uniqe ability of Fluorine atoms to repel pretty much anything. Both work in different ways, so what one is better is really determined by application. A quick pros list for NiB compaired to Ni Teflon, NiB is harder, wears longer, and has a higher temp range, and is a slightly easier process to apply. Ni teflon is probably easier to clean due to Fluorine in it and has more of a "self lubricating" aspect to it if you can call that a thing.

Either way, at the end of the day.

[mrgein]

NiB is an awesome coating, im sure something else will come out that potentially "beats" it but i wouldn't buy a NiB from just anyone, mine was done by AAC in a complete upper. I hear the teflon NiB is a little superior to just regular NiB but im not a chemist in any type of meaning.

Nickel Teflon and Nickel Boron are simmilar in that they gain wear resistance and corrosion resistance by using nickel but they achieve the friction reducing properties differently.

NiB when plated to a metal builds up in tightly packed columns with a dome top, like in this picture.


That surface acts sort of like billions of tiny ball bearings, the surface area that is touching and sliding is greatly reduced. Also because they have a much larger surface area that aids in dissipating heat. Thats why this coating is used in things like saw blades to increase the life of the blade.

Nickle Teflon on the other hand uses the properties of teflon, or more precisely the uniqe ability of Fluorine atoms to repel pretty much anything. Both work in different ways, so what one is better is really determined by application. A quick pros list for NiB compaired to Ni Teflon, NiB is harder, wears longer, and has a higher temp range, and is a slightly easier process to apply. Ni teflon is probably easier to clean due to Fluorine in it and has more of a "self lubricating" aspect to it if you can call that a thing.

Either way, at the end of the day.

^LOL that was awesome. so which would you say is superior for more humid climates like arkansas?

[rpk47]

Corrosion wise, either is fine. Typical use where you shoot maybe a few hundred rounds on a range trip I doubt one could tell any difference between the two. We are really splitting hairs to find any noticeable difference in this application.

Me personally I would go with NiB. The reason why is the physical structure of NiB. Sure nothing sticks to teflon but at the surface where the parts slide your going to have wear of some sort. NiB is harder and therefor will last longer. Plus the dome shape of NiB is going to do a fantastic job of gently polishing the upper where they contact. If your upper is NiB coated well then you have nothing to worry about.

Also NiB by its nature decreases the amount of surface area that actually touches, while increasing the surface area to dissipate heat generated by friction. It's a win win, less heat and more area to get rid of what heat is generated.

[Harlequin1138]

Thank you all for providing awesome answers to my question. I'm glad I picked up s NIB BCG. Gonna have to save up for a AAC one for later.

[300Blk]

Normal NIB has the same concerns that I raised for DLC.

Nickel is only highly corrosion resistant if it is a thick layer of the high-phosphorous type. Problem is, almost no one does a thick layer because they would have to custom make the part to allow for the thickness of the nickel. Also, that kind of nickel is not as hard and wear resistant.

So they use a thin coat of the harder kind with boron at an attempt to stay in spec with standard carrier dimensions, but then there is not as much corrosion resistance.

AAC uses a thick layer of the corrosion resistant but softer nickel on an custom machined carrier with a hard layer of wear-resistant nickel-boron as a top layer. The dimensions of the carrier were calculated so that it ends up in spec when the thicker dual layers are applied.