You going with the AI version of the 280?

Unlike many AI cartridges the 280AI offers a rather significant boost in performance over the vanilla 280 Rem.

Part of the reason is the slightly increased case capacity but the big reason is the 65,000 Psi SAAMI MAP for the 280AI. The 280 Rem has a MAP of 60,000 Psi as a consequence of having been introduced for the semi-automatic Rem 740 rifle.

Can you load the vanilla 280 to 65K? Sure you can but you'll be on your own because nobody publishes 65K data for the 280 Rem.

162gr Amax's at 3050 from a 26" tube is something you simply will not see with the 280 Rem.