All I read here are
OUTDATED solutions.
THE fastest way to go with the current version 1.45 (Season 28) is:
1) Select
Adventure Act II , normal difficulty.
2) Hit down on the
(D-Pad), go to act tab, and select Archives of Zoltun Kulle.
3) When it shows "
Bounty: Kill Zoltun Kulle." Go there!
4) Walk straight ahead and go into the large circle (Soulstone Chamber).
5) Kill Zoltun and his two elites.
6) Quit, rinse and repeat.
Why?
A: The bounty shows up most of the time, if not exit out to the main menu and go right back in to refresh.
B: You do not need to "wait" for the save icon to appear everytime
, as mentioned in other solutions. After the kill count and bounty successfully done, go to OPTIONS > GAMEPLAY and select/de-select "Elective Mode" (since it is on top, the first one). This will trigger the auto-save everytime. Now you can exit to the main menu.
C: The bounty takes literally
12 seconds to complete. Yes I stopped the time!
Hope this more accurate solution helps!