Re: 280rem loads
I've been shooting Rem. Model 721 w/24" bbl in 280 Rem. for about 30 yrs., and yes you can get to 2900 fps, but your brass will suffer. Reuse will be no more than about 2-3 times, and check for pressure signs on bolt face/primers. I have used the Sierra 160 gr. BTSP and Nosler 160 gr. Partitions with good results over 54.6 gr. of IMR 4350 and a Large Rifle Magnum Primer (CCI or R-P). This pushes out at about 2800, and out of my gun shoots sub MOA (best 5 shot group ever was 0.324" at 100 yds. with the Sierras). At 250, Sierras about 1" and Noslers about 1.5".
I looked at the newer powders and just haven't seen the need to go there yet. That extra 150-200 fps m.v. isn't going to change the point of impact significantly until you get way past the range I'm comfortable with and capable of seeing clearly thru bifocals.