Spam ST x infinity.

If you're interested in improving mass pulls, this is an easy rotation that can be done at basically any gear level:

Pull everything together -> Infuriate -> Unchained -> OP -> Berserk -> OP -> Vengeance -> HS -> Bloodbath -> Maim -> OP spam

You can also use Steel Cyclone over Unchained if you want to save Unchained for bosses or it's on CD and move your buffs earlier in the rotation. If you're comfortable enough with the dungeon you're running, you can also drive-by HS one mob from a pack then drive-by Maim a mob in another pack to get up Maim early and basically just spam OP, popping CDs, and etc.

CDs are important for big pulls as you'll be taking a lot of damage, but WAR's CDs are more active and based on the damage you're dealing so you'll need to know when to use and when to save certain stuff. You can basically alternate between Vengeance and Thrill + Conv per pull as all 3 sit on a 2 min CD. As you run more dungeons you'll get used to the flow and it'll be a breeze. @50 nobody really single targets down things unless they're MNK (even then they'll throw in some AOE), so keeping AOE aggro is basically all you'll be doing outside of boss fights.

Good luck!