I have a Savage 110 300 win mag. I'm thinking of building off that action. I'm not sure do I keep the same caliber or do I change. I really like the 300 rum, 338 rum, and the 338 edge the 300 wsm is sweet too. I will be using this for long range. I have a custom 7 stw that is my hunting rig. I'm wanting a hart barrel 30" not sure what twist yet. And a McMillan a5. What if any of these calibers will work and which do y'all like? What barrel would y'all use and at what twist? Trying to stay around $2000-$3000 on this.