Overloaded Backwash
From Halopedia, the Halo wiki
In Backwash there is a glitch which is very easy to do. First go to one of the bases and change your weapon for the Sentinel Beam, change the Sentinel Beam for another one, wait a few seconds and another Sentinel Beam respawns with the previous Beam in the map, repeat the process any time and only if you move the Sentinel Beams with an explosion they will dissapear.
