I have hunted in the "West" 5 or 6 times. It isn't that hard to do when you live only 50 miles from the Atlantic. I would probably fit right in with the OP's magnum question. My most often used traveling rifle has turned out to be a Ruger 77 in 300 Winchester mag.
In hunting new areas of the country, I seldom ever knew what type of terrain or cover I would be hunting or a typical range that the game would be encountered. It has almost never matched the description that was provided by the Outfitter selling the hunt and I want to be prepared for what ever I get into. My elk was shot at a range of 435 yards. I had no idea I would be taking a shot that far off and to me it was a long shot. I was comfortable with it and had practiced at 400 yards in preparation for the hunt. I was told to expect something in the neighborhood of a 200 to 250 yard shot. The 300 Winchester magnum was up for it. My 308 probably would have been too. I was comfortable with the 300 Winchester.
On a hunt a couple of years ago to Texas, I had no information on the typical range to expect for a shot at a white tail. This hunt I carried a 6.5/06. I first saw the buck at 175 yards. He was walking towards me and I shot him at about 80 yards. I was ready for a 400 yard shot, but got one I could have made with my 35 Remington with no problem.
A bear was shot with the 300 Winchester at 15 yards. He died right where he was shot. I was not disappointed. Mule deer at 140 yards, Pronghorn at 295 yards, a fallow deer at 35 yards, axis deer at 75 yards and a caribou at close to 400 yards.
Most of my hunts have been the "once in a lifetime hunt". I knew I wouldn't get to shoot an elk, bear, pronghorn, caribou, or mule deer but once. I wanted to go with a rifle that I knew would get the job done, whatever that turned out to be.
I probably hauled a rifle all over the place that was heavier than it should have been and chambered for a cartridge that was more powerful than I needed, but I felt ready for any shot I might get and it worked every time.
