I have killed lots of elk and deer with Sierra bullets in 270 and 30-06, but would not worry too much about the Speer bullets either. Last year I shot an elk and a deer with the new wiz bang eld x bullets in 6.5 creed. and thought they were way too soft and explosive. Shot another elk with the 6.5 140 gr Sierra GK and had better penetration and less meat damage. The best answer I can give you is witch ever one shoots best out of your gun will be fine for deer.
