RE: Smallest caliber for elk?
What has changed allot in the caliber game is the new quality bullets available in factory loadings.
Hand loaders have always been ahead of the field at being about to buy custom bullets.Todays Nosler accubonds are one of the best.These bullets allow higher velocities with light weight bullets that retain 75-85 % of their original weight.
If you are serious I would look into a .264 Winchester magnum. You can achieve velocities these others only dream of with very little recoil!