Overloaded Backwash
From Halopedia, the Halo wiki
Overcharge Backwash is a spawn-related glitch present in Halo 2's Multiplayer map Backwash. It allows players to duplicate Sentinel Beams.
Walkthrough
First, go to one of the bases and take a Sentinel Beam. Swap the Sentinel Beam for another weapon, wait a few seconds, and another Sentinel Beam will respawn despite the presence of the first. Repeat the process for as many times as you like. Moving the Sentinel Beams with an explosion will cause them to disappear.
