The Savage 22-250 is the non standard 1 - 12" twist. People are demanding to shoot heavier bullets in their .224 caliber rifles. Savage went from the standard 1 - 12" twist in the 223 to 1 - 9" twist because their customers demanded it so they can shoot heavier (longer) bullets. I like to shoot the lighter bullets in my .224 caliber guns. I bought a new barrel for my Stevens 200 and it has a non standard 1 - 14" twist. It shoots 50 V Maxes very well and I have no problems stabilizing 55 grain bullets. This is obviously a personal choice. With a slower twist rate, you can push bullets a little faster than a fast twist rate. I would think you would have no problems shooting 60 grain bullets with your Model 12 and if you wanted to convert it to a 220 Swift, in that one either. Since these guns develop higher velocities they may be able to shoot some thing even heavier. Bullet stabilization is a function of bullet length and velocity so the faster you push a bullet the less twist you need to stabilize it. A 1 - 14" twist may stabilize a 60 grain bullet in a 22-250, but a 1 -12" twist may stabilize a 65 or even heavier bullet, depending bullet design. Bare in mind that most reloading books use 1 - 14" twist on their test barrels/guns so start low and work up carefully if you are hand loading. Good Luck and Good shooting.
