I do not have any experience with the 80g myself, Hornady's site states 1: 8 min.I thought that too. But the box I just got say 1-7", as does Berger Barrel Twist Calculator. But I've been shooting them in my 1-8" twist .223 and they seem to be stabilizing.
Not a huge difference in oal between 75eldm and 80eldm
75eldm 1.119"
80eldm 1.153"