fatjake,
Limited experience here. Short story made into a long story. I have a Weatherby Mark V Ultralight six lug. The action is 1.140" diameter. I have a Pierce titanium action (Remington clone). It is 1.350". Both carry 26" barrels. The Pac-Nor barrel on the Weatherby measures 1.091" in front of the action. It is lighter than a number one contour. The Christensen carbon wrap barrel is the same size as the action. Both barrels weigh forty ounces before I fluted the Pac-Nor. If it is important both are eight twist.
The accuracy of the Christensen barrel has been about 3" at 400 yards for three shots, so it's okay with Barnes 127 LRX and Nosler 140 Accubond. I received some Alco 160 grain very low drag bullets to try in it. I am waiting for a trigger. The other trigger punked out on me the first season.