Re: .280 or ??
I have a 280 and use 150 Nosler BTs. The rifle has taken several antelope out past 500 yards without a problem. Low recoil and very flat shooting , it's fun to shoot. I also have several magnums, big and small, but this is a good all around antelope and deer rifle in my humble opinion. Are there better, I'm sure, but it depends on what you want. The 280 works very well for the mentioned animals.
Some have taken elk with it also, but I like the bigger magnums for elk.
My two cents!