Looking for a quality Nickel Boron coated BCG, I currently have a WMD carrier in one rifle and have been satisfied with it however they’ve apparently switched over to faceted carriers without forward assist serrations so they are no-go for me now.

Not looking for some high end enhanced carrier that’s adjustable, just a quality milspec carrier that’s machined nicely with a nickel boron coating.

Any suggestions?

Don’t really care about price just want a solid BCG with those features.

Nickel boron sucks for a BCG coating.  

There’s a guy with a few new BCM phosphate bcgs in the ee.

Get a Sionics NP3 instead.

Why does it suck?

Low lubricity and fouling sticks to it.

Full hard chrome is the only thing I’d besides phosphate.

I don't think it sucks. I have tons of rounds on my Failzero.

I’m pretty sure you got that completely backwards.

Lubricity is the ability to reduce friction and a phosphate BCG will create more friction than any smooth coated BCG.  Fowling does not stick to a Nib BCG more than it would a phosphate.  A phosphate BCG is not smooth, it has a very, very fine texture.

The one thing that has me concerned with Nib carriers is flaking.  It has not happened to any of the Nib carriers I have but the coating process would play into this.  The same can be said for chrome plating.  They are both coatings.

If you were to go with a Nib BCG, make sure it’s from a reputable company.

The phosphate on the contact points of the carrier rails quickly wears off and is a highly polished surface after a few mags.

Nib is hard as fuck and doesn’t do that, and as mentioned it is possible for it to flake.  

The bottom line is that carrier finishes are almost insignificant.  I guess pick whatever color you like but don’t think it’s any kind of an upgrade.

I've got three NiB bcgs, one failZero, one cheaper ($89?) AimSurplus and one of Aims little more costly ($99-109?) and all have been flawless and I can't complain. NiB is good to go, very slick. I know at some point in history one company spit out a batch that had some chipping/flaking issues, whether that was from poor metal prep before plating or improper plating process I can't remember. When that happened I was like well shit I better get that outta my gun but decided to keep it in and monitor it. Well that was many years and many rounds ago and there is no change with them - flawless.

I've got several with old tried and true chrome lined phosphate and no complaint either.

I've also have a couple nitrided BCGs and really like them also. No complaints.

I've gotten where I prefer either NiB or Nitride over phosphate because they are just slicker. The NiB is the easiest to clean of the three. My guns that came with good quality phosphate just work and stay in.

With any of these finish/treatment options the more important decision should be picking good quality manufacture. Many of the companies that offer BCGs use Toolcraft but sell as there own.

i had some flaking issues with a NiB carrier too. it also sucks for suppressors use, they tarnish fast and that creates drag.

had good luck with a Nitrided toolcraft one though for suppressor use.

Standard bolt carriers work fine. I own a couple of DLC carriers and they work fine too. It's my personal opinion that all "improved" coatings are Gucci fluff and have zero positive impact on performance or wear.

I like Continental Machine Tool GI BCG's if I can get them. I prefer Carpenter 158 MPI bolts over any other option.

Nope.  Not my experience either (WMD).  If you are getting fouling, you are using too much lube.  NiB should actually be run with very little lube on the NiB surfaces of the BCG carrier and bolt.

According to KC Jones, one of the best known and respected companies doing industrial, commercial, and military nickel-boron plating (I think they actually invented the process):

"Nickel boron has a significantly lower coefficient of friction than chrome, HVOF or PVD, making it an excellent product because of its built-in lubricity."

I have NiB, nitride and phosphate bcgs.  Each works fine.  NiB is superior, IMHO, for applications where the rifle will be run hard in dirt, mud, water and with little or no lube.

Here is a good read.  Download the 3rd party torture test of Fail Zero (firearms division of longstanding NiB company UTC Coatings) NiB bcg versus mil spec phosphate in full auto M4A1 operation until failure to fire in various extreme operating conditions:

https://www.failzero.com/fz-news/item/failzero-outperforms-legacy-systems-in-dept-of-energy-live-fire-tests.html

I put a NiB BCG in my BCM upper about 4 years ago, so far no unusual wear.
Also have a few Nitrided BCGs, also no indications of unusual wear.

Between the two, I’d pick Nitride just because it’s been out longer and gets used in a lot of barrels that see more wear than BCGs.
But if you like shiny things, nothing wrong with NiB. But I also wouldn’t spend more than $10-$20 for a coating over phosphate.

My rule of thumb is if it runs wet, phosphate. If you prefer dry, Nitride or NiB.
Coated BCGs also seem to be a bit easier to clean although if you’re using a sonic cleaner it’s all the same.

And the quality of the make is much more important than coating. I’ll take a plain ol’ phosphate Toolcraft over any no-name BCG regardless of coating.

I agree with the phosphate Tool craft being just fine. They work. But the Nitride are here right now if your looking for them.

https://www.righttobear.com/AO-Precision-Nitride-Bolt-Carrier-
Group-p/aom16-hpt-mpi-sbn.htm

https://ar15discounts.com/products/nbs-223-5-56-bolt-carrier-group-black-nitride/