Probably wanna ask this in the reloading section, you'll get more replies.
So I load on a Dillon 650, it really helps with loading volume and you can still load for accuracy too if you use a digital scale. Too much to go into here regarding the Dillon but loading for AR in general may require the use of a short base sizing die. If you have problems feeding using what you're using now then you'll know. You wanna load to mag length because it's usually a limit here. Uh, work 'em up like you would with any other rifle.
Not much difference really... Just be careful where the brass lands because it can get beat up more using a semi.
Some powders do better than others, some meter better than others. Varget is popular for semi's but I've been using H335 to mimic M855 ammo. It's pretty dirty stuff but I use suppressors and that makes it worse. But, it works, and it seems to get the velocity up there without too much pressure.
I also like LC brass for AR's. Tougher, lasts longer, just better IMO. Oh, and use the military CCI primers, they're harder preventing accidental discharges but still lend to accuracy. From what I understand, they're basically BR (match benchrest) primers with a tougher cup and a magnum loading --so beware when working up loads.
Good luck, stay safe. And check out the reloading forums.