AR Bolt Carrier Finishes - which is best?

[Tombs]

Is titanium nitride a stronger or the strongest coating?

Try to keep in mind, it's wearing on aluminium and the hammer.

It's not like it needs a ridiculously hard finish, it just needs something to keep carbon from caking on easily. And ideally something that holds oil well, so that it doesn't wear on the receiver too much.

Almost like phosphate on the outside and chrome on the inside is ideal!

 

[DMTJAGER]

I spend A LOT of time at www.ar15.com and www.m4carbine.com (trying to hard to educate myself on all things AR-15) which are among the best websites for the AR platform of rifles. Experts on the AR platform, combat vets with a considerable experience using AR's while fighting and School trained and certified AR armorers make up a considerable portion of both WS's membership. Questions concerning AR BCG's come up constantly, which BCG finish is best is frequently among them.

More than a few AR experts, experienced combat vets and armorers at both WS's strongly prefer and recommend a phosphate finish for the BCG due to Phosphates rougher finish resulte in a inherent ability to allow lubricant to adhere to it much better than Melanite or other similar exotic extremely slick and hard coatings like titanium nitride, nickel boron which allow lubricant to flow off of them due to they being such a slick surface finish.

I have chrome lined BCGs with phosphate, melanite and nickel boron outer finishes.
I have at least 5ks rounds through each of them and did notice the lubricant adhering to the BCG with the phosphate finish better than the ones with melanite or nickel boron, but I can not say as it mattered as none of the rifles they function in ever gave me a single issue what so ever.

But these my AR-15's used in a purely casual application of recreational shooting in a very low dust environment. An M16A1 or M4 carbine used in combat in Iraq or Afghanistan is in a much much MUCH more severe desert environment exposing all small arms (and pretty much everything else) to the fine talcum powder like sand of that region so keeping a rifle clean and functioning reliably requires a lot more frequent maintenance than any state side AR-15 does.
And the AR-15/M-16/M4 carbine platform of rifles are designed and intended to have their BCG's greased and well lubricated hence the term "Running your BCG wet" so one would have to admit at least in theory your BCG having a finish that aided lubricant to stick to it would be a significant advantage VS one that did essentially the opposite and allowed lubrication to flow off of it's surface.

 

[bwframe]

Also, more so than finish, buy a decent brand.

Youtube school of the american rifle, lotta good info on that channel regarding AR platform.

 

[Jarvitron]

All I run is AOPrecision phosphate bolts. If I were going to upgrade at all it'd be to a Sharps XPB in DLC.

 

[Squid556]

I own phosphate, nickel boron, and nitride.

Surprisingly, nitride is my least favorite. It appears to be wearing much faster than the other finishes.

Phosphate seems good and I can attest to its surface holding onto lubricant better. I just really dont like the grittyness of it. No functional issues. This is the milspec so its no doubt good enough.

Nickel boron is my favorite. I enjoy the look and feel of it. Finish is holding up well. Easy to clean. Naturally slick. The Fluid Film I use holds onto it pretty well.


Toolcraft sells them in every configuration so I doubt any of them are truly bad. Heres what they say

Coatings - Toolcraft, Inc.

 

[DadSmith]

I own phosphate, nickel boron, and nitride.

Surprisingly, nitride is my least favorite. It appears to be wearing much faster than the other finishes.

Phosphate seems good and I can attest to its surface holding onto lubricant better. I just really dont like the grittyness of it. No functional issues. This is the milspec so its no doubt good enough.

Nickel boron is my favorite. I enjoy the look and feel of it. Finish is holding up well. Easy to clean. Naturally slick. The Fluid Film I use holds onto it pretty well.


Toolcraft sells them in every configuration so I doubt any of them are truly bad. Heres what they say

Coatings - Toolcraft, Inc.

Most of my BCG' are phosphate. I do have a Fail Zero NiB BCG in my Aero Precision AR 10 build.

AR10 (.308) BCG | FailZero BCGs

A completely assembled, ready to install .308 Bolt Carrier Group

www.failzero.com

It's very slick, and so far holding up well.

 

[JAL]

My list:

• Chrome all the way around is the considered the best possible, but you're going to pay for it, when you find them.
• Followed by phosphate with chrome lining, albeit they require more cleaning effort.
• DLC comes in at a close 3rd with an extremely hard coating molecularly bound to the steel, and it holds lubricants very well, plus it cleans very easily.

I'm using DLC as the chrome are more than I want to spend, and they're much easier to clean than the phosphate -- having lived with phosphate BCGs in the military for two decades.

 

[Ruger_Ronin]

This^. Beat me to this very vid. I would have never thought about the coating in the threads of gas key screw, thus creating a false torque value.

All that said, I'm still using NiB ...one Toolcraft, one FailZero. IME, I have seen NiB perform better in colder temps. Perhaps natural lubricity? The phosphate seemed to "hold" carbon more and required more frequent cleaning