While talking to a sporting goods clerk I used to shoot with, we got going on how powerful of rifles modern shooters seem to think they need. He had a call from a customer that wondered if 200 grain bullets in his .338 would be good enough for deer as he had run out of his usual 250 grain loads. The store clerk had shot a few deer with a .357 magnum rifle. I find myself as guilty as any. I traded off a perfectly good 38-55 for a 45-70 because I felt the 45-70 would do a better job and have regretted it since, as I would have a hard time finding another rifle like it and probably would have to spend far more than the original price to get one. I have been working on 215 grain bullet loads for a 8mm Turkish Mauser because of that same mentality, when I have an excellent load for my 303 British and a 30-30, both of which will adequately harvest deer. Dead is an absolute, you cannot make a game animal deader.
Some, like Daryl, obviously enjoy shooting big guns, and I am not critisizing them for that enjoyment. A larger caliber in the hands of a good shot has certain advantages such as better blood trails and possibly more knockdown power. Also, if there is a chance of running into a Grizzly or Brown bear it may give a certain sense of comfort. On knockdown power I am not so sure. In my younger days, an experienced hunter told me that if a deer is shot in an opening it will probably run to cover, regardless of what it is shot with. (This is shots to the lungs, not broken shoulders spines, etc.) If it is 100 yards form cover it will run 100 yards, if 20 probably 20yards. My experiences seem to verify that this is generally true in that most will run to cover before dropping.
Just thought it would be fun to hear others experiences and thoughts.