Hi guys,
I'm just learning about AR-15's and am trying to educate myself in order to prepare for a purchase in the not so distance furture. I've read about the Nickel Boron (NiB-X) coated Bolt Carrier and wanted to know how important it might be to have this included in the AR-15 purchase? Also, I've read about and additional EXO coating that is applied over the NiB-X. Thanks for the help.

NiB
eNiB
NiB-X

All three of these are variants and/or tradenames of the process used by difference companies. eNiB is essentially different than the other two because it is an electroless process that can be applied to raw aluminum, where the other two can not. For aluminum parts, we have found Nickle Teflon to be far better in providing the desired results, and original NiB best on steel parts. We use original recipe NiB from Fail Zero on our NiB BCG's and Battle Triggers. NiB-X is a tradename used by WMD Guns. EXO is the tradename used by Fail Zero. From looking around the internet you may have come across quite a bit of conflicting information.

Having a NiB BCG in your upper makes clean up a total breeze. You can take a large dry patch and wipe off the entire BCG (after breaking it down). I use a small feeler wrapped with the patch to get the edges inside the bolt face, but the rest wipes right off. After that it is just a little EWL spread micro thin around the bolt and then reassemble.

You'll also have a cooler running upper, as the coating resists heat soak far better than phosphate and chrome coatings. And last is the lower likelihood of the bolt getting gummed up, since you're not using barely any lubes or greases and it has an almost glass like finish that provides a low Cd or Cof (Coefficient of drag or friction).

Excellent. Thanks.