Unlike Dee, I love to try different calibers on big game. Deer are my favorite big game.
There are deer and there are DEER. When I hunted in Tx. one of the first trips, I was allowed to shoot 3 or 4 does on the hunt. The first one I took was a real surprise. The ranch I was hunting had lots of deer. As the first day drew to a close, I decided to fill one of my doe tags. A small herd of deer was feeding and I selected the biggest out of the lot. I used a 243 if I remember correctly, at the shot it dropped. When I got to it,I felt like a bambi murderer, it was very small. At camp, I was embarassed to bring it in, but found it was a big doe for the area.
Bucks were a bit bigger, but not much.
In W. Va. the area I hunted, the deer ran a good bit smaller than deer shot in central Pa.
Some of the mulies we have hung up in Wy. were horses compared to these deer. A couple I could only load in the truck by hauling them to a drop with the pickup and rolling them on the tail gate.
So when we talk about perfect deer ballistics, there is a wide range of animals, and hunting conditions. In W. VA. and Tx. deer were shot over bait. One often had time to select his animal, and make a perfect shot. Here a lighter rifle would work well. Also I suppose in much of the south, where deer are shot over food plots usually from a selected stand. So ranges are known.
In Pa. conditions were different. No bait. Often in the areas I hunted heavy pressure. One had to make a shot in short order and have the animal down in a short distance or some vulture would have a tag on it before you found it.
Here in Wy. ranges can tend to be long, unknown, and the deer much bigger than other areas I have hunted. Not all bucks are horses, but when one lucks on to a big one they are awsome.
Some have to be seen to be believed. Usually, old trophy mulies make very few mistakes. When they do, you must take advantage. You won't get a second chance a few days later in the same food plot, or bait pile. For example, one of my pals hunting the wilderness in the western part of the state found a mulie with a 40" + spread. There were four hunters in camp, it was decided to make a stalk the first morning from the four escape routes, someone was bound to tag this trophy of 3 life times.
When the stalk began, the old buck was laying on his point where he had been for several days. When the stalk was over, he was gone, never returned, and no one had seen him escape.
So when we talk about perfect deer ballistics much ground is covered. For much deer hunting though the south and east, the old .30-30 is good for close cover. With country like Pa. that has lots of pressure, I used my grandfathers old .30-06 to good effect plus several magnum rifles for shooting across strip mines.
These or the .270 class would suit for shooting on food plots in the south. For the west, last season I used a .30-30, .300 Sav. and 7mm-08. On some of these hunts I did not expect a chance at a trophy buck. But any where I hunted that I had a chance at a real whopper, I carried one of my .300's or 7mm mags. If that magical monster buck ever crosses my path, I want to make the most of it. It may not occur for several more life times.