Usage had no impact on choice of rib material. If the rib is damascus there is a higher probability the barrels were bored and joined before being shipped.
Why a different pattern on the C grade? Because no one was going to the waste money by using a fancy billet for rib material. The billets were made at the rolling mills. The barrel makers had to purchase them. The fancier patterns were a premium and made in smaller numbers by the rolling mill. These mills did NOT exist to make gun barrels. They were producing all sorts of materials. The gun barrel business was a side line for them.
Pete
