Stoneshatter drop rating?

[Lyvanna]

Yeah, so I've been running DM west roughly 15 times the last days. Never once have I seen this epic little crossbow drop.
Does anyone knows roughly the drop chance? Wowhead says one thing, atlasloot says another. But either my luck is terrible or the drop chance is lower than they tell me.
Also, does anyone know if there's any other fancy twists to it? I noticed a chest I can't click under the stair thing, think it activates after you kill Immo'thar or something - does it possibly drop from there?

Not entirely sure if this is the right place to post, but I figured since it's for hunter transmog... Feel free to send me to another forum, lol.
Thanks in advance.

[Agent Mercury]

Uh...
It is Blue.
It drops from Prince Tortheldrin.
No triggers.
RNG is RNG.

[Lyvanna]

Uh...
It is Blue.
It drops from Prince Tortheldrin.

I know. By epic I mean, it looks epic. I know where it drops from. I've killed the prince dude around 15 times. Never once seen it drop.

[Agent Mercury]

I know. By epic I mean, it looks epic. I know where it drops from. I've killed the prince dude around 15 times. Never once seen it drop.

That is RNG. No triggers. Keep at it.

[Lyvanna]

That is RNG. No triggers. Keep at it.

Guess there's nothing mysterious to it then. Thanks.

[Deleted]

My friend got it in two runs, a little tip to make the run faster is that you do not have to kill the pylons to get to the prince..
So just run down and kill the tree guy and run straight to the library

[Siri]

The chest below the stairs is just there to turn in a quest you complete inside the instance, it doesn't have anything to do with killing bosses (other than completing the requirements for the quest)