I have been using a Sionics NP3 BCG in one of my uppers. In under 1000 rounds, it appears to have significant wear of the finish at the contact points. It is perhaps best seen in the third picture linked below. The same pattern can manifest on phosphate bolt carrier groups, but I had hoped the NP3 would be a bit more durable than the phosphate. And yes, I do lubricate the gas key, rails, and port holes before every range session.
As we know, the bolt carrier group only makes contact with the receiver at contact points such as the four carrier rails and the gas key. If the NP3 is worn through in these areas, then any lubricity advantage with NP3 in regards to reliability becomes moot. You quickly end up with 8620 steel on anodized aluminum at the contact points, even if the parts of the carrier that glide along without contacting the receiver are coated in NP3. As such, I question whether this carrier would have any reliability advantage in adverse conditions over a standard phosphate carrier. If anything, it may be at a disadvantage if the non-contact points of the carrier hold on to lubrication with less affinity.
The carrier has worked flawlessly, and to its credit is incredibly easy to wipe clean. When I contacted Sionics I was told that the wear was normal, but they offered to allow me to return the carrier and discuss the issue with Robar. If this is indeed normal, I reasoned that it would not do any good to have it re-coated because it would quickly return to this condition when I shot it again anyway. I would not argue that it is defective or inferior to phosphate carriers, but I am now skeptical that there is any advantage to NP3 beyond ease of cleaning because the coating appears to wear off the contact points fairly quickly.
Have others had this experience?
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