My choice for our deer has been the 100 gr. Sierra Gameking @ 3000 fps. Have shot a truck load or two with it and no complaints. However, our deer are not big at all. I've only used this bullet on deer up to 180lbs. with many sub 100lb does in there; drop in the tracks are normally what I get. The 257 Roberts is really not hard on bullets so I think most any deer suitable one will work.
GreggH
