I put release agent on the action and rough up the bases. After set I remove, clean/drill out the mounting holes in the base, wash off the release agent and retighten the base down. It is still removable, fits better, and removes the sponge that Marc mentioned.
I stopped by Badger Ord. in Kansas City to but my base and rings, and they suggest that I used Loctite green or red on the base. They told me to clean the parts with a degreaser and apply a thin film of Loctite. The main reason is to prevent rust. Hope this helps a bit.
I use either devcon or accraglas to bed the base to the rifle, some actions tend to have some wide tollerances in dimentions, a little bedding compound under the base helps take up the difference and ensures you don't warp the base (just remember not to screw the base down 100% tight until the bedding has cured unless you know that your reciever is 100% true.)and it prevents the base reacting to the reciever and prevents any water getting in causeing rust.