Just about any bullet will work on "deer sized" game including elk, as far as the .280 Rem. I've had good results with the Winchester Fail Safe's over the Nosler Partitions. I had Federal premium in N.P. on my first hunt with my .280 and the deer ran off with a broadside hit behind the shoulder. I racked the rifle the rest of the season. The following year I switched to Win. Fail Safe's and dropped an 8pt where he stood. Every deer since then has either dropped in their tracks or not ran over35-40yds.
The Fail Safe's or the Grand Slams would be a better choice over the N.P.'s, also the Swift A-Frames are a good choice.