Wraith Twin Vipers – Max Burst 66k Sustained 16k. Primed Mods

You can also use this build in the Void, just replace the Expel mod with Pistol Pestilence/Jolt/Scorch/Frostbite.
This will drop the Burst to 57k and DPS to 14k.

This is the highest DPS build possible, it is not ammo efficient.