My Whelen is a twelve twist and 22 inches long. I used the twelve because that is what I had on the shelf. If I had to order the barrel, I would probably have ordered a fourteen and seen absolutely no difference in performance! My twelve twist shoots all 250's very well, 200 spire points poorly (2.5moa), 225 Sierras poorly, 200 RN very well, 170 FN very well and 158 FN very well. I think there are other aspects of rifle building which are much more critical than twist; providing the twist is adequate for the bullet length. GD
