I use my Browning .280 BAR with Winchester 140 grain Silvertips for Western Oregon Deer, although I've used it to hunt Mulies and Bull Elk in Eastern Oregon as well. Flat shooting, good all around gun.
I have to agree with Goosehunter. Somewhere between the 25-06 and 270 would be ideal. The only exception would be if you are hunting an area where it is likely you'll have a tag or chance to harvest bigger game animals. I've always liked the 308 b/c it will have a little more knock down power to take out a bear if I see one during bear season. A lot of bears around here are killed by chance and being in the woods at the right time. It's good to have the extra power if needed. The 308 is also an excellent long range caliber.
I would have to agree with that. The .308 is an awesome caliber and one that at some point I will probably end up owning. It will probably be in a unique rifle though like a sjingle shot (ruger no. 1 maybe). The point about encountering larger game is a good one as well. A big component to be added there is that bullet choice is going to need to be looked at to. If there is a chance that you will get a shot at a larger animal with a more hardy skeletal system, you aren't going to want to use that same fast opening, rapid-expansion bullet that you would normally use on deer. You'd have to find something to fullfill both roles. Which in this day in age of a million bullet choices... shouldn't be all that hard.
I also think it depends on where and what type of deer. out here if your hunting blacktails a 223 or 243 is about right as they are a small deer, for whitetails or mulies a 243 or larger would be good, i use my 30-06 for everything and to me its a little much in th way of blood shot meat. I would love to add a 270 to my collection and that would be my dedicated deer gun.
There is one tip I have learned over the years in hunting whitetails in late season snow. Do not overlook soybeans left standing on the edges of fence rows, woods, creeks, buildings wherever it might be, this is where the deer will be while the food lasts during late season. December/January will pull deer in from some distance away to feed on the easy to get to food.
I killed one of my nicest bucks off of a very small patch of soybeans that was left after rains created a...