My new project is a 6mm ackely improved on a savage action. I'm thinking of a 1/9 twist for bullets in the 100gr range. Probably a mcgowan varmint contour barrel with a muzzle brake. The one thing I'm having trouble deciding on is barrel length? How long do I really need? Weight is not a huge issue, but I don't mind having a shorter barrel if I can get away with it.