It is a cut rifled steel barrel and that is all the bullet ever see's. They then remove material from the steel barrel blank so they have space to wrap carbon fiber around the steel barrel profile. The carbon fiber never comes into contact with the bore. So like any steel barrel cut rifled, CHF, Button, Broached the limiting factor is normally throat erosion and crown erosion. The reason Proof barrels are accurate is because just like Krieger and Brux they make very good cut rifled steel barrels. I have yet to see any research performed by a third party engineering firm that their carbon wrapping of the steel barrel they make actually does anything that is statistically significant repeatable way. Kind of like carbon fiber shift paddles in your BMW does not make the car any faster it is just man jewelry. You have to differentiate yourself from the large pool of custom barrel makers some how! Price is one way and gimmicks are another.
