ARC: Heavy Shot vs Straight Shot

[Odd]

As Ernesto said it adds a 10% buff to crit chance for 20 seconds.

But don't use heavy shot next.

Straight Shot>Bloodletter>Wind Strike>Venomous Bite>Heavy Shot. Spam Heavy Shot after that, Bloodletter/Misery's End whenever available, and keep dots up on applicable fights (boss fights where there's still time for full duration dots). Keep Straight Shot up as well. Omit whatever abilities you don't have yet, but still follow that order.

A VERY useful macro for Bard is this:
/ac "Misery's End" <t>
/ac "Bloodletter" <t>
/ac "Heavy Shot <t>

If you just use this macro it will always use whichever one is available first. So at the start of a fight, the first time you hit this it will use Bloodletter. Then apply your dots and continue hitting it. As long as Bloodletter is on cooldown, it will use Heavy Shot, until near the end of the fight, when it will use Misery's End. To sum it up, as long as both Bloodletter And Misery's End are on cooldown/unavailable, Heavy Shot will be used.