This quest is not available in game.
Bring Rumbleshot's Ammo to Hegnar Rumbleshot in Dun Morogh.
Hegnar Rumbleshot sells guns off the road to Anvilmar. Riflemen and mortar teams spend a lot of time practicing out near his shop, and he's always needing fresh ammunition.
But... the last crate of ammo I sent him got lost along the way. My courier said he was camped near the Grizzled Den when wendigo chased him away... and the fool left Rumbleshot's ammo behind!
<name>, can you get that ammo and take it to Rumbleshot? He's been waiting on it and I'm sure he's running low.