The Flawless Arcanite Rifle is crafted by Engineers with a skill level of 300.
The components are:
- 10 Arcanite Bar
- 2 Thorium Tube
- 2 Essence of Fire
- 2 Essence of Earth
- 2 Azerothian Diamond
- 2 Enchanted Leather
The drop rate for the schematic is reaally low - 0.4% according to Thottbot. But on most mature servers, the schematic can be easily bought on the AH because it is byproduct of Powerful Mojo farming.
If you prefer to farm the schematic, consider this:
- Trolls drop a lot of Runecloth, some greens and even blues. Clean your bags before venturing into their valley.
- Nearly any troll hut can have a chest. Many huts means a good chance of an active chest nearby, so every 15 mins or so run around and check every hut for treasure.
- Avoid Scouts if possible - the first time you hit them they run for their friends. The good thing is that there are two ways to avoid fighting troll groups: (1) Start fight with any movement-inmpairing ability (such as hunter's Concussive Shot); (2) Just run to a Scout and wait until he attacks you first.
- Left and right of the pyramid are two rich Thorium veins with high respawn rates.