My 338 Edge has a 30" 9.5 twist Obermeyer bbl that sends 300 gr Accubonds at 2900 fps into a nice triangular 1/2" cluster at 100 yards but will not shoot the 300 gr Berger OTM's or Hunters into less than 2" at 100, going to do up another barrel for the rifle in 338 Edge with a 30" 9.3 twist 5R Bartlein specifically for the Berger bullets, 338 Bartlein barrels and 338 Berger bullets seem to be made for each other