For match bullets in 280Rem, I recommend trying the 162 AMAX, the 168gr Berger VLD, and the 175gr SMK (or the 180gr Berger).
For the 162gr AMAX and RL19, the max load should be somewhere around 53 grains and starting at 48 should be safe.
RL17 would be a good candidate for the .280 Rem, but I don't have any load data for it on hand.