I think the Amax design went to the wayside a while ago. I used 178 Amax for a while.
ELD has since seemed to replace that line. Wether you can buy the Amax yet I don’t know
That said, measuring things like bearing surface and base to ogive on both Amax and ELDX 178 I will say the ELDX line is much more consistent.
I had differences of up to .017” in base to ogive in 1 box (100 bullets) of the Amax.
The ELDX seem to be more in line with Sierra Match King consistency. Which for the most part was .001”-.003” difference base to ogive in the box I measured
I really like the ELD design and have had great luck with the ELDX on whitetails