I’ve used bolt carrier groups of all types, low end to high end, mil spec parkerized, dlc, nitride, nickel boron, chrome plated. I now only use quality mil spec phosphate bolt carrier groups. I’ve had the plating flake off of both nickel boron and chrome plated bolts and carriers. I had a young manufacturing national match bcg that wouldn’t headspace well with any barrel. The bolt closed on a nogo gauge in a criterion and a WOA barrel. The nickel boron bcg was from spikes tactical, and the plating started chipping off of the bolt face and carrier rails after only a couple thousand rounds. I’ve had several nitride treated bcg’s and while they’re easier to clean and feel nice and smooth when I charge the rifle, the small parts like the extractor, or the lugs on the bolt are more susceptible to breaking due to the fact that the nitride treatment makes small parts more brittle. I’ve had several nitride extractors fail on the range. Both times the lip on the extractors sheered off, and stopped grabbing the case rims. Both times I quickly replaced them with mil spec phosphate extractors that I had in my bag, and i was back in business. If you want that smooth feeling you get from a nitride bcg I’d recomend using a nitride carrier from a reputable company paired with a mil spec phosphate bolt and extractor. In order to apply coatings like chrome, dlc, or nickel boron, parts must be made under tolerance, to account for the surface coating that will be going on top. I personally don’t trust parts that were made under sized, and depending on a coating that is susceptible to cracking and flaking to bring the part in to spec tolerances, particularly on a bolt face. I want to be able to count on my rifles in any situation for long periods of time before I need to start thinking about replacing extractors, bolts, gas rings, etc. I use mil spec bcm bcg’s because I’ve never had any issue with them and I’ve used them hard. I don’t care if they’re harder to clean, gas gun bolts are not meant to be brought back to “right off the assembly line” white glove clean, they’re meant to be cleaned practically, lubed up, and used. I’d recommend either BCM or toolcraft phosphate bcg to anyone looking to put together a reliable all around use or duty gun. If you’re looking to ring out every last bit of accuracy from a precision f-class or bench rest rifle, then maybe a lantac enhanced bcg might be for you, but most people don’t shoot well enough with gas guns to be able to tell what difference one bcg or another makes in their rifles accuracy.
