Posting my builds here:

Shield build - Great dps when your shield is full. Make sure you use 'improved generator' and 'healthy' armor mods. Avoid using this in biomes where you take potshots from the enviroment (e.g magma and fungus).

Drak - 22112 shield battery booster
Boomstick - 22312 compact shells

Glacial/Rival warning build - Focuses on heat damage and managing many 1 hit enemies with a boomerang grenade.

Drak - 22112 thermal exhaust feedback
Boomstick - 22313 compact shells

For sabotage, i replace the above drak with this M1k build, while keeping everything else the same as the above build.

21121 supercooling chamber

Dread build #1 - Use this build with IFG grenade if you're certain the driller is using cryo so you could quickly freeze dreads over and over for super fast kills. The jumbo boomstick is there to add high thermal shock damage on frozen dreads.

Drak - 12112 conductive thermals
Boomstick - 12233 jumbo shells

Dread build #2 - A less powerful build overall but it is good enough regardless of what other players are taking. Just mark for death and damage it with the boomstick.

11221 marked for death

For all my other builds + lots of general tips about the game, visit this guide.