Over the last 30 years, I have tried about every metal heat treatment, plating and coating there is to the AR. The engine building business has been using nitriding, chrome plating and anti-scuff coatings for ever. I always thought I was way ahead of everyone , being able to see these methods in extremely harsh enviroments and temperatures. Fact is, all I was doing was splitting a gnats ass and making myself feel good. Fact is your basic bolt carrier and upper will go 50,000 rounds if you half way take care of it. I have seen plating fail way to often. Spray on coatings work and will definitely give extra life but eventually wear off also. I have seen hundreds and hundreds of times ex. valves with nitrided stems, have over 300,000 miles on them and everything in the engines is worn out except the stems on the valves. I know this is not a rifle but that valve runs at 700 degrees plus with very little lube. No bolt carrier even comes close to that abuse. I would take a nitrided barrel over chrome any day. Plenty will not agree and that is fine. If you like bling, plating is the way to go. You can not convince me there is anything better or more durable than a nitrided carrier and it is the shit when it comes to the bolt itself. The bolt is under a high load type friction. If you look at almost every type tool steel there is, once you get over rockwell C scale 50-55, you start to loose toughness or impact resistance.With nitriding you can retain a core hardness of 50-55 for toughness and have a surface hardness of 60-65 for wear and abrasion. This is just my opinion based on what I have seen over 36 years. Craig