Re: 280 ai
Any max 280 Remington load is your starting load for the 280 AI. I fire formed my cases with 57.0 grs RL 19 and 140 gr BT's. A properly chambered AI will give you a slight crush fit with a 280 Remington case so there is no need to seat the bullet into the lands or used reduced loads with cream-o-wheat filler. Just load a max 280 Remington load and fire form your cases.
The best powder for the 280 AI is RL 22. My best accuracy, as recommended by my gunsmith, was with Federal GM215M magnum primers.