I've never had to opportunity to hunt elk, but a 280 will certainly shorten the like span of a bull mose in a hurry. Shot placement always critical regardless of calibre. http://www.chuckhawks.com/280Rem.htm
280 Remington shooting 160-gr. Nosler AccuBonds or Partitions is great elk medicine. If this fine cartridge had been introduced 3 years earlier, then Winchester might not have even brought the 270 to market and we'd be ranting about the improved 280 Rem rather than the 270.
If you're lucky enough to be on private land and can leave your stand up during the off season you can tie an old piece of cloth or something of the sort to your stand. I like to use an old camo bandana that I have. That way the deer get used to the movement and eventually don't bother even looking up when there is slight movement. This may just give you the time to draw your bow or raise your gun without being detected.