World Of Warcraft- need hunter help for DBW?

i play MM hunter..... on other bosses i have very good dps.......... but when it comes to Deathbringer surfang..... others manage to do more then me........... dont know if they do AOE on the creeps or something but they beat me always on this boss else m better at other bosses...... any tips???? or how can i improve my dps......... Because usually top DPS gets the DBW or top 5-7 gets to roll......