I had the occasion to chronograph an individuals rifle at the range one day. He had an NEF as sold by Walmart in .280Rem. Those rifles had laminated stocks and a 26" bbl.
The 140gr Federal/Nosler Partition ammo he had was chronographing at 3,100fps. Exactly 50fps less than some handloads I was testing for a friends 7mmRemMag from a 24" bbl the same day.
The recently "legitimized" as in SAAMI standardized .280AI from a 26" bbl will match the 24" velocities of the 7mmRemMag and do it with 10gr less powder and noticealbly less recoil.
Whats ironic is that I had planned on rechambering a Remington Mod-7 I obtained in 2004 to .284win which is a short-fat version of the .280. I made the "mistake" of chronographing it with factory ammo before dispatching it to a gunsmith. I'm getting 2,900fps with a 140gr bullet and have seen 3,000fps from a couple of handloads...... from a 20" bbl !!!!
For elk, even a 140gr bullet properly placed will drop elk where they stand. The 160gr is even better. Particularily a "premium" such as the Nosler Partition or Swift A-frame.
However, my 7mm08 has recently been upstaged by another Mod-7 in .260Rem. Not quite as much gun as the 7mm08, it's twice or better more accurate. Individual groups with 120 and 140gr bullets for 3-shots have been one-hole, and 5-shot groups under 1.0".
You'll enjoy a .280, and perhaps even more so, a .280AckleyImproved. You can even shoot .280Rem ammo in the .280AI.....