Speed kills up to a point. Please do not confuse me with the folks that really know anything on this subject. However, I have shot a bunch of deer with a variety of rifles and nearly identical situations. What I have seen indicates that there is blessed little difference in what a 25-06, 30-06, and 35 Whelen do at comparable ranges on comparable whitetail deer, trying my best to take out both lungs and the top of the heart.
In some cases the deer run a little bit, but in nearly every case, I can stand where they were when I shot them and see toes in the air. In each case, I am getting an exit wound. All these deer have been taken with 175 yards.
The idea that speed buys distance is a good one. What else I can add is that if the bullet has enough speed to open up and you are getting an exit wound, the difference between 25-06 and 35 Whelen is largely being spent in the dirt on the far side of the animal. If I had to take a pick for which does the best job, I'd not take the 35 Whelen . Overall, the best job seems to be done by the 30-06 using either 150 or 165 grainers.
