The .280 AI, for all intents and purposes, is a 7mm Rem Mag without the belt. Velocities generally run about 100 fps under the 7 Mag with similar loadings of bullets. This is a good cartridge to form and load. If using re-formed military 30-06 cases, be sure to back off the charges a little, due to thicker case walls.
The Nosler 5th Edition reloading guide has a listing for the .280 AI.