The .280 is a great caliber! It will have no problem with the game you have mentioned, but it is bullet choice and shot placement thatare most important when it comes to taking a particulargame animal anyway. (Well to a certain point
)Heck I know people who have taken plenty of Elk and Bear with a .243.
You would have more selection of factory loads with a .270, 30-07, or 7mm though. All of which are very capable.