First of all:
not my idea, i just repost this.
It´s no big secret, that with the recent Patch (1.04) Vault (Trail of Cinders) has been buffed to 1500% weapondamage over 3seconds.
If you got now stacked Sharpshooter, u'll have about the double amount of weapondamage.
Vault (Trail of Cinders) does not consume the stacked Sharpshooter.
As long you dont autoattack any mob, your damage will stay high.
If you are able to combine with a decent gear of resistance, this should also work well in act3 and maybe act4