Certified Gameaholic
Engineer rifle
Full-crit build brings the most out of Rifle. Generally you’re going to have 30 in Firearms, 30 in Tools, Berserker’s amulet and crit-oriented runes e.g. Scholar.
In Firearms pick Rifle-oriented traits to maximize range/damage/cooldowns (can also pick Sitting Duck for weakness stacking with Rifle 2).
In Tools you pick Static Discharge, and something out of Speedy Kits, Scope, Power Wrench or Adrenaline Implants.
The remaining 10 points can either go into Explosives (Incendiary Powder) or Alchemy (Invigorating Speed, with Speedy Kits you can have permanent Vigor!).
For slot skills take Med Kit, Rifle Turret, Toolkit and something out of Utility Goggles, Grenades or Battering Ram depending on you. I personally prefer Utility Goggles, puts a 15-stack Weakness on enemies right off the bat and the 20sec Fury + Blind immunity ensures maximum sustained damage.
Basically engage the enemy from maximum distance, unload all toolbelt skills and use Rifle 2 and 4 smartly to CC enemies. Also remember Rifle 5 does a ton of damage if you land on enemies, you can also use it to get away or jump large gaps. This build can do some of the highest long-range burst in the game.
If you get into trouble you can use Toolkit 4 (3 sec block), Toolkit 3 also hits hard and applies 5 stacks of confusion. Oh and Toolkit 5 is a 1200 range pull…hilarious on Skyhammer or pulling enemies off capture points.
Speaking of pulling people, it’s possible to “displace” someone to a completely different location using Tookit 5 (1200 pull), Rifle 2 (immobilize), get behind them, Battering Ram (450 knockback), Rifle 3 (450 knockback). They’re now 2100 units away from where they initially were, or in Skyhammer’s case they are dead 
It’s a very fun build but look out for Thieves, Necros and Mesmers! They can kill you very quickly if you’re not careful.
GL
(edited by Wintel.4873)