So far I have the Hornady 162 ELD-M and Hornady brass.   I have a supply of Fed 210 and 210M primers.  We have a gun show next weekend and I want to get powder.  I'm seeing Reloader 19, 22, VV N165, H4831, IMR 7828.  I have quite a bit of IMR 4895.   Any suggestions where to start?

lol, Rob I was just on there.  I think I am going to try H4831sc and start from there.  Any thoughts?

Sounds good, thanks

I don't have a .280 AI.  I do have three different ..280 rifles, however.  All of them shoot a variety of bullet weights well with RL-19.  It produces highest velocity, too.  I don't know how much difference the slightly greater case capacity changes things.

My most accurate load for hunting uses the lighter 140 grain Berger VLD Hunting bullet over 56.0 grains of RL-19 and Fed 210 primer. Remington once fired brass, flash hole deburred, case length trimmed and mouth chamfered.  That's all.   In a Rem 700 Custom Shop Mountain Rifle, the load development work stopped when two five shot groups were under .7 MOA.  One group was right at .5 MOA.  That is a Douglas sourced 1:9.5 twist 24" sporter profile barrel.

I don't know how much this would help you shooting a heavier bullet.   All I can say that is bullets between 140 and 168 grains RL-19 has been very good in my rifles with the standard chamber.  H4831SC has also worked well for me in the standard .280 chambered rifles.

Yeah I saw a lot of people are using RL 17, 19, and 22.  I read several internet threads about temperature sensitivity with the Reloader powders.  Hard to say if that's true or just BS.  Have you had any issues with that?

Edit: I was thinking 28 NOS, so my original comment is less relevant.

280 AI is likely in the range of the H4350's and RL19's. Something along the lines of H4350 through H4831 should find you good accuracy and velocity.

H4350 was used for ages in the 7mm Rem Mag, which probably as close an analog as there is.