RoRG only drops from A1 bounty cache (or A4, which has the entire pool of bounty only items) why I was spamming it, by not grouping I did it to myself I know, but I've always been the SSF type for these games. Takes about 10-15min to run A1 solo for me. PC, I haven't owned a console since a PS3 for drunken CoD Zombies ages ago.You'd be better off running t16 bounties in a group, finish all of them in the same time it takes to do 1 round of a1's and it gives you a bonus chance at getting the rings. No reason to target farm any specific acts bounties (on PC at least, not sure on console).
For pure farming nonsensically fast, WW barbs and multishot/strafe DH are god tier stuff and good for mindless playing.
Necro is pretty mindless right now with season class mod(more than usual), 87 GR and I just blast elites/RG with AotD, and hit command skel to keep them bouncing around. I was pretty lucky getting all the other drops I needed early on to complete my build, just that damn ring holding me back. For pure farming I scale back to 65-70, and everything just vaporizes, even with some gold/MF stuff equipped.
Might do a barb, but been eyeing the corpse explosion builds, still one of my fav skills, I just don't recall it being very effective past leveling before. Loved it in OG D2.