slee,

My suggestion is to try it both ways. For what it' s worth, I' ve shot the hollow base Hornady Great Plains out of my Knight, with & without the wonder wads and it made no difference in accuracy. I have been told since then that the wads don' t help on hollow bases, but that they are beneficial with the flat base bullets.
That makes sense, as you would expect the center of the wads to blow up into the center of hollow base and away from the bore walls - while a flat base would cause the wad to flatten out and make more contact with the bore walls - improving sealing & cleaning.