I have a 6.5-06 AI built by Kirby Allen. It sports a 26" barrel with a 1 in 8.5 twist. Although that barrel was chosen to shoot the 140 gr. bullets, it never liked them. I went with the 130 gr. AB running 3,150 fps. Ballistically. about the same as the 140 gr at slightly slower speeds. I recently transitioned to the 160 gr. matrix at 2,950 fps. More hitting power down range with slightly better wind bucking capabilities. IMO, still a little light for elk, but it could be done. Absolute hammer on deer/sheep.