Ten years ago I had an old Remington ADL 270 rebarreled to 280 Rem. I left the barrel finished at 25.5". This rifle is at its best with full doses of IMR4831 or RL19. I use RL19 behind the 140 gr. Nosler BT or the Nosler Partition. I am .5 gr. over max in the Nosler Manual #4. Groups are under .5" as long as I am having a good shooting day. I have recently worked up a load with the 175 gr. Partition. Again I exceed the listed max by a little. Accuracy is .75" and recoil isn't too stout. This is my elk load if I get the chance to go. I always use Federal primers and Winchester Nickel brass. As for an accurate factory load mine will shoot the 140 gr. Winchester BST nearly as good as my reloads. Something I forgot I get 3100+ fps out of the 140's and am just shy of 2800 fps with the 175's. The 175's are on par with a 30-06 and 180's but you have morre sectional density, higher B.C., and a flatter trajectory. You made an outstanding purchase and when you have some results let us know. Another shooter I know uses the 175's in front of IMR7828 and can exceed 2800 fps in a 24" barrel Rem. 700 BDL. Best of luck.