So it's been annoying me on my dh, that once I turn on sharpshooter, the dps shown is absurdly high. This is because blizzard uses a really simple formula for dps that uses the crit chance assuming it is going to be static.
But crit chance is a dynamic, varying value with sharpshooter on.
So I've built a tiny true dps calculator here.
Demon Hunter True DPS with Sharpshooter calculator
The way it works is, it calculates your damage over a period of time assuming an increasing likelyhood of crit, but weighing the later periods down by less because it's less likely. I'm willing to debate the math with anyone who's curious enough.
What it means is, if you turn on sharpshooter and start shooting at mobs, this is likely the damage you'll do per second averaged out, which is a lot lower than what Blizzard will show you