14 twist is plenty for any bullets short of the 300 grainers. My Norma is a 12 twist and it will stack the 225TSXs well under an inch but so will a 14. No reason really not to go 12 unless you want to shoot cast bullets; rumour has it the slower twist may be more accurate with the pistol bullets.
Mine is a 22 1/2" PacNor on a M70 classic stainless magnum length action, it started life as a 300Wby.
Great cartridge. Mine likes 74 grains of IMR4350 for 2800 fps with a 250 grainer, or 73 grains of Big Game for around 2900 fps with the 225.
