Thread: carbon fiber vs steel

Hey guys and girls just a question that's been bugging me for a while. We all know that a carbon fiber barrel of the same weight is stiffer than steel , well so all iv'e read and been told says so. What no one seems to know or I can't fine is when does carbon fiber equal steel? Say something like a barrel with a fairly standard profile of say 16mm at the muzzle and heading towards 30mm at the action. What diameter would a carbon barrel need to be to equal the stiffness? I see on christien arms site for example their carbon fiber barrels for a blaser is 22mm at the muzzle apposed to 17mm steel. Just wondered if there was a rule of thumb , say multiply x25% to get a close equivalent or something along those lines?