No disrespect taken.
I'm well aware of the salt bath ferritic nitrocarburizing process case hardening process known as Tenifer (Glock) and Melonite (S&W).
The issue is that the Tenifer/Melonite treatment isn't commonly performed on AR barrels. S&W is the only manufacturer I'm aware of that offers it.
If I'm going to build a 300 BLK, .308, etc... I want the properties that a chrome lined barrel will provide.
S&W does sell a M&P 15 upper chambered in 300 Whisper that uses a 4140 steel, Melonite treated barrel. It can chamber the 300 BLK, but I want a barrel specifically chambered for 300 BLK.
...but these plans are a long way out. Before I dump money on my "dream" build, I want to have a bunch more fun with my two AR 5.56 platforms first. The ammo is much more affordable.