A topic I know something about. I can say that a stainless H-Bar elite 24" AR I built a decade ago was the most accurate 5.56 I ever saw. For durability though chrome lining cannot be beat. There is a slight loss of accuracy due to the chroming process not being able to deposit a perfectly even layer of material. This is true with electro-plating as well as the chem only electro-less systems in use. I don't know if anyone re-grinds the lands (this would help accuracy). If some company could devise a way to grind both chromed lands and grooves, I think they would have built a better mouse trap. Or at least a better mouse shooter.