Alot of people complain about RF aren't viable especially in solo play. I've been experimenting on various combination of builds since 1.08 release on PTR. Here is my result for RF bombardment solo farming build I currently use on PTR.
"wait wait.... what's TotH doing here?" one might question, but this passive play major role fore solo farming build. One might say it's a key for solo farming, without TotH you'll pretty much find hitting with Bombardment a hard job to do. TotH roots mobs every 7 secs combined with AOE of Bombardment it's become a good immobilezed hatred spender.(of cause this work well or even better with other RF rune too) Now you don't have to kite much and can aim at ranged.
Besides all those pros, TotH aren't great against most elites or bosses as you'll end up face tank those by the way.
Last things I want to mention is SS. This is vital skill if you want to stand still and shoot like Rambo. When fighting eliets, face tanking chanelling RF, you have to bear in mind you are taking risk of dying at anytime, so prepare to pop your SS when things gone wrong or even kite a bit
(It's based on your own expirence when to stand and keep chanelling or when to move out of the scene)
here is my video MP10 Farming (a bit harder for me as I usually play on MP7)