Phessor,
I shoot Savage rifles and I use the 2 piece picatinny rail type, but only the ones made of steel. I do not like the alloy ones by Weaver as they are not adequate in strength. Since a lot of Savage rifles have no floor plate and must be loaded and unloaded from the top only, it is advisable to have a two piece or a cut out one piece. Again, I like the steel bases and only ones that use all four mounting screws.
Good Luck,
HB