I asked that same exact question... With the Nitride finish they do not bore coat them. The Nitride is far harder than the bore coat making the bore coating not necessary. I still have a bunch of reading to do on the specific process that Knight is using. But one of the steps has something to do with a lubrication process.I have been trying to research the process on line - but in all honesty I am not smart enough to understand all of it - but still doing the research....This is a small sample of what I have found.

Ferritic nitrocarburizing or, less commonly known as Ferritic nitrocarburising, in British English, is a range of case hardening processes that diffuse nitrogen and carbon into ferrous metals at sub-critical temperatures. The processing temperature ranges
from 525 °C (977 °F) to 625 °C (1,157 °F), but usually occurs at 565 °C (1,049 °F).

Parker Ferritic nitrocarburizing
ISONITE® Salt Bath NitdridingISONITE® (per SAE AMS 2755) is a high-performance variety of salt bath nitriding process. It is also known as Tufftride® and Liquid/Salt Bath Ferritic Nitrocarburizing (FNC) process. It is a thermochemical diffusion process whereby nitrogen-bearing salts generate a controlled release of nitrogen at the interface of a ferrous part.

BENEFITS

And again I am still researching...I can tell you my Rain test worked out great! After a few hours on the deck in the rain I brought rifle in let it dry then wiped it off with a dry rag - It still looks new!!!