A lot of this depends on terrain and your fitness. A highly accurate and lethal 338 rifle is useless if you can't handle getting its weight into position to shoot the animal.
Last year I hiked ~8 miles into the back country in pretty steep country to shoot an elk at 730 yards 1000ft vertical over my position. I was shooting a 13lb 338 Edge. I have a couple lighter rifles in 300WM and 358 but given wind conditions that day, on an expensive and difficult hunt, I would not have taken the shot with any rifle but the 338. There is no replacement or displacement and my 338 dropped that elk in 1 shot while the guy who shot the herd bull before me was within 200 yards and he pumped 4 rounds of 7mmRM into it to bring it down.
In a "once in a lifetime hunt" I would carry the most capable rifle I could. For elk, the 338 if I could hack it. If not, a lighter 300WM or at closer ranges the 358. Frankly I have little use for rifles under 30 caliber on elk. I know a lot of people do but when you drive 1500 miles and spend nonresident tag money the equation changes. Elk are tough and while 7mm works for many I know a few who shot elk with one and didn't recover.
Last year I hiked ~8 miles into the back country in pretty steep country to shoot an elk at 730 yards 1000ft vertical over my position. I was shooting a 13lb 338 Edge. I have a couple lighter rifles in 300WM and 358 but given wind conditions that day, on an expensive and difficult hunt, I would not have taken the shot with any rifle but the 338. There is no replacement or displacement and my 338 dropped that elk in 1 shot while the guy who shot the herd bull before me was within 200 yards and he pumped 4 rounds of 7mmRM into it to bring it down.
In a "once in a lifetime hunt" I would carry the most capable rifle I could. For elk, the 338 if I could hack it. If not, a lighter 300WM or at closer ranges the 358. Frankly I have little use for rifles under 30 caliber on elk. I know a lot of people do but when you drive 1500 miles and spend nonresident tag money the equation changes. Elk are tough and while 7mm works for many I know a few who shot elk with one and didn't recover.