Achievement strategy: Help the Bombardier!
The daily quest for the Help the Bombardier! I’m the Bombardier! achievement, Fire from the Sky, is found in Uldum; coordinates are approximately 41, 5. You need to complete almost the entirety of Uldum to get access to this daily, since it’s based on the non-daily quest of the same name.
The achievement says “Kill 10 mobs with one artillery shell”. The most important thing to remember is this: the achievement lies. After the first shell hits, you have approximately 5 seconds to hit with another shell and get your remaining kills.
Shells have a travel time. A shell targeted at the parts of the mountain that are furthest away from you will take longer to hit.
Shooting a shell has a cooldown, but not a global cooldown. If you spam the “1” key right after you’ve clicked with your mouse to target, you’ll be able to shoot a second shell immediately, despite the cooldown.
When you keep that in mind, the achievement becomes extremely easy even if there are multiple people doing the daily at the same time. Shoot a shell at a faraway group, then immediately shoot a shell at a close one. They should hit in quick succession and you sohuld get the achievement.