A while back, Hornady announced they'd halted production of the Amax line, and a few other bullet styles. Aside from paying out your a$$ on gunbroker, your best bet is calling around to the 'mom & pop' stores in your AO and maybe see if ya get lucky. Google/Bing searches are a waste of time, as you're one of many, many, many shooters looking for the same "backordered" product.
That said, I recently built a fast twist .22-243AI, and needed a stash of Amaxs to keep it, and my .22-243Win, happy. With a little bit of legwork and non-search engine driven scavenging, was able to find a few thousand each of both 75 and 80gr Amaxs.
Amaxs of every caliber have been as rare as hen's teeth, but they are out there...somewhere!
Only other option is to put WTB posts up on shooting site's classifieds and see if ya find a charitable soul willing to part with some of their stash...
Good luck in your quest!