About This File
20 bag Drop about 30%
24 bag Drop not sure.
Run at Northrend
Not 100% AFK you need click to open the door. run about 3-4 times you will get 20 bag.
http://www.wowhead.com/zone=4809/the-forge-of-souls
Kill
http://www.wowhead.com/npc=36497/bronjahm
Drop