I don't have any first hand experience with this but since no one else has given any input I'd give you something to go on.
I think you'd want the lightest bullet that you can shoot accurately. My Sierra DVD rom has load info for a 110 and 125 bullet. The problem I've run into when trying to shoot light bullets from a gun not specifically made for that is poor accuracy. Generally the best accuracy from a rifle will bewith the heaviest bullet available that your gun will stillstabilize.