Poor? I had it in mind it reads as (for its age) a better than 'poor' cartridge. I looked up some info and I reckon it would still easily take a deer or two today.

Quote from CH`s

The original factory loads included a 180 grain FMJ spitzer bullet at a claimed muzzle velocity (MV) of 2800 fps, and a 146 grain spitzer hunting bullet at a claimed MV of 3100 fps. I say "claimed," as I understand that these loads actually delivered less velocity than specified. They still traveled right along, however, particularly the 146 grain bullet that may have delivered MVs of 3000 fps. Later factory loads advertised a MV of 2550 fps for a 180 grain bullet, and a MV of 2900 fps for a 140 grain bullet.

The .280 Ross became popular enough to be picked up by both Remington and Winchester, who offered factory loaded ammunition until 1935. These included, I believe, a 150 grain SP bullet at a MV of 2800 fps and muzzle energy (ME) of 2610 ft. lbs. Contemporary British factory loads gave a 160 grain bullet a MV of 2700 fps and ME of 2600 ft. lbs.