You cannot go wrong with the 308 or 30-06. If you are looking for instant kills you can shoot for the front shoulder. This is where I shoot if I want to anchor a whitetail deer. Not all will drop on the spot but I have never trailed a deer more the 50 yards when shot clean through both shoulders. I use 120 gr. Hornady HP's out of my 25-06 loaded to about 2950 fps and have no trouble getting pass thru's with this load on deer. I live in Oklahoma so in my area a nice buck will only weight about 115-140 lbs field dressed.

I do prefer the 30-06 to the 308 as I think it is more adaptable to shooting 180 gr. bullets. However, there are factory loads available with nosler partitions or barnex tsx that will penetrate a deer stem to stern. Place any of these bullets through the front shoulders of any deer and it is impossible for him to go far. More than likely it will not move more than 10 feet.